iapennell

The weather has finally turned colder, a couple of days with north-westerlies from inside the Arctic Circle. Early January 2016 has been wet and still quite mild- snow rather than rain and that is at over 400 metres up in the North Pennines, but at least we now have an inch of snow and it was -4C last night. Looking at the weather charts it looks like the current cold snap will not last beyond the weekend- back to Westerlies next week. I did not believe that a Sudden Stratospheric Warming high over the Arctic was going to occur and result in a bitterly cold January with weeks of hard frost and snowfalls, and lo- it hasn't happened! In retrospect strong El-Ninos, the westerlies high up over the Equator (Quasi Biennial Oscillation) and the still-active phase of the sunspot cycle have conspired against blocking patterns occurring in high latitudes that would be required to lead to weeks of bitter north-east winds from northern Russia. However, February remains the best bet for real cold snaps this winter, but these will be short sharp affairs delivered on northerly or NW winds from the Greenland Icecap, rather than weeks of bitter easterlies: The Jet-stream remains too strong for that. There is a possibility of cold northwesterly winds at times persisting into March too- particularly for those of us living in the North, this is thanks to a large patch of colder-than-normal water in the NW Atlantic close to 45N and the fact that- in the eastern North America and Greenland sector at least- Arctic pack-ice extends further south than usual.

Well there is just an inch of snow lying where I live near the village of Nenthead (North Pennines) and the temperature finally went down to, wait for it, such a frigid -4C! This, of course, is at 410 metres' elevation and it is the much-hyped (for about ten days now) spell of "Arctic weather" with snow and "down to -15C in Scotland" that's been all over the Daily Express, Mail and some of the excitement on this Forum has been generated by weather-forecasters too eager to cry "Wolf, Wolf!". Already, looking at the Met Office and BBC charts there are signs that the supply of cold air from the Arctic will be cut off by Saturday with just the high maintaining the frosty nights; said high looks to be slipping south by Saturday so milder North Atlantic air coming 'round the top of it will spell the end to the short-lived cold snap! I would just like to know what Fleet Street would do if we had some REAL snow and hard frosts! What we have had over recent days is nothing really out of the ordinary, especially not for those of us living in the North of England- ITS CALLED JANUARY! Its actually nice to be able to walk outside and across the land without getting sodden wet. BTW some really nice scenic pictures on here of two inches' snow with frost glistening in the sunshine- we live in such a lovely part of the World.

Allowing homes and businesses worldwide to put aerosols and SO2 into the atmosphere would also encourage fog to form more easily in autumn and winter months in middle latitudes. The top of a layer of fog fog acts like a snow surface in that it reflects heat from the Sun (albedo 0.6 or above) but longwave terrestial radiation from the top of a fog layer is strong; hence the formation of fog with clear skies above results in a strong heat sink. Aerosols near the surface are very good at encouraging fog formation but clearly there also needs to be a supply of moisture and a near-surface radiative balance conducive to the formation of fog then its persistence. Extra aerosols in the atmosphere would weaken the oblique rays of the autumn and winter sunshine in mid-latitudes to encourage radiation conditions conducive to fog, but there is no way the right conditions for its formation (and persistence) over a large area would happen in the tropics. Extra aerosols in the atmosphere also encourage the formation of clouds higher in the atmosphere; so there would be a small increase in cloud-cover. The tops of clouds are (on balance) much colder than the radiative surfaces below that they replace so reductions in long-wave terrestial radiation caused by increased cloud-cover are substantial, but clouds also reflect a lot of the sun's heat back into space (albedos are typically 0.6 to 0.7). On the whole increased cloud-cover has a net cooling impact on our planet. So increased fog and cloud-cover would greatly slow global warming as CO2 levels marched inexorably upwards. It is, of course, a moot point whether humankind is prepared to adjust to living in smoky towns and cities (with regular winter fogs); my take is that adapting to it would be less painful and certainly less deadly than billions of folk worldwide having to cope with rising sea-levels and killer summer heatwaves in both low and middle latitudes. I would be interested to hear if some of you have some more ingenious ideas about how to fight global warming head-on (or indeed whether we should do) should the situation arise whereby governments cannot muster up the collective will on a global scale to reduce CO2 emissions and we reach dangerous "tipping points".

btw an interesting dilemma- In the view that CO2 levels are rising and the Earth is creeping towards a level of warmth that will promote irreversible changes (i.e. masses of methane outgassing from Siberian permafrost leading to catastrophic warming, disintegration of Greenland Icecap) is it so wise to insist that all countries insist their industries and homes don't put aerosols and sulphur-related compounds in the atmosphere. Sulphur dioxide and aerosols in the atmosphere intercept some of the Sun's heat and act as a buffer against global warming. Medical knowledge and facilities are much better than 60 years ago so people can get treatments/medication to prevent a lot of respiratory problems that could result. This would not cost ££ billions, it would just involve a relaxation of legislation. It could buy us another 20 years. Anyway, what are your views.

There is certainly merit in exploring whether we could use nature to help fight against rising CO2 levels by, for instance planting trees on a very large scale so that these would take up carbon dioxide. Other initiatives include putting large amounts of iron filings on the sea surface in an attempt to encourage algae, developing and planting drought-resistant plants in dry regions that would absorb CO2 from the atmosphere: These are all things that should be done sooner rather than later in an attempt to stop CO2 levels rising too much; then we would not have to employ Geo-engineering solutions in say, 40-50 years' time! All these solutions would cost ££ billions, certainly to do anything on the scale required to make a tangible difference. The other thing about trees and plants; trees tend (on the whole) to be darker than the bare ground they replace and so absorb more heat from the Sun and the moisture they put into the atmosphere (through evapotranspiration) has different impacts dependant on where this happens: At high latitudes in autumn (above about 50N) where the trees could still be evapo-transpirating the Sun is weak so the importance of extra clouds reflecting more heat from the Sun is not as important as moist cloudier air preventing the heat near the ground escaping into space. In winter at high latitudes dark conifers take up no CO2 when they hibernate and absorb a little more of the Sun's heat (weak though it is). Elsewhere and at other times of the year in high latitudes a lot of the Sun's heat is taken up to make chlorophyll and to convert CO2 back into oxygen; the Sun is strong in the tropics and at higher latitudes in summer so the effect of more cloud cover is likely to be a cooling as well. However dark palm forests/plants established over bright subtropical deserts is likely to stimulate warming- the atmosphere contains more moisture so the net radiative heat loss at night is less and the dark forests absorb more of the Sun's heat than barren rock or sand. In moister savannah type areas the increased moisture is likely to stimulate cloud cover sufficient to reflect the strong tropical Sun. It does depend on the trees used; more palm trees and more rain-forest type trees in the tropics and subtropics (outside the most arid deserts) would work. This type of vegetation grows quickly (given the heat and enough moisture) and takes a lot of the Sun's energy in photosynthesis so it is likely to have (over time as CO2 levels stabilise) a profound cooling effect. At higher latitudes too, deciduous trees that produce white blooms in spring and bright yellow/gold leaves in autumn (these reflect more of the Sun's heat than dark conifers which also, like deciduous trees, still don't evapo-transpirate in winter). White or light-coloured plants and flowers planted over wide areas (rhodedendons with white flowers, oilseed rape, cotton) could be developed and grown over large areas and not only would these take CO2 from the air but also reflect the Sun's heat. There should be serious R & D put into developing resilient easily-multipliable hybrids of white or pale-green grasses that could be expanded en-masse across the agricultural plains of the World. As regards algae, research into developing plankton and algaes that are able to duplicate quickly, thrive with the right conditions and (better still) be light in colour to reflect heat from the Sun (as well as absorb CO2) would prove invaluable. Since we are talking about tropical ocean surfaces (over which the Sun is high) changing an ocean surface with albedo 0.05 to one with surface albedo 0.2 (or even 0.15) could help greatly in the fight against global warming. All these things should be researched into; it is perhaps surprising that the World's best brains are not already onto much of this!

Looking at the predicted jet-stream patterns, the strongest upper-Westerlies are over the NE Atlantic (currently near 200 mph about 50N) at present and they are predicted to cross northern France over the weekend into early next week. Meanwhile a strong ridge is predicted to be developing NW Atlantic to Greenland (effect of colder-than-normal waters in NW Atlantic). It is certainly not weak upper Westerlies and my take is that this will be coming from north-northwest if it unfolds. If the strong jetstream remains just a few hundred miles further north and the ridge is less pronounced in the NW Atlantic rather less cold westerly winds will prevail and that will bring (certainly to lowland southern central England) conditions that most folk would not consider to be truly wintry (i.e. some showers of sleet and hail with only ground-frost at night rather than air-frost). All the same this is remarkably similar to what unfolded mid-late January last year; a few days of northerlies from the region of Svalbard could bring daytime temperatures near freezing point even to the South with snowfalls almost everywhere and with nighttime minima below -5C over a wide region.

Dear All Thought that, in the light of COP21 in Paris that produced lots of hot air and an absence of commitment to specific measures to steer the World towards carbon neutral within 50 years I would kick off the New Year of 2016 with discussion about what happens in 50 years' time if CO2 levels are still rising past 550 ppm and global temperatures reach dangerous levels above pre-industrial levels: To Geoengineer or not to Geoengineer, that is the question. And if we do Geoengineer and cannot get measures past the United Nations do we form a Coalition of The Willing- say the UK, USA, Canada, Germany and France- to commit to specific measures to reduce global temperatures (like H-bombs over remote Pacific islands, securing and bringing to Earth asteroids then firing at the south-side of Arctic mountains at noon in June to reduce the tilt of the Earth and keep high latitudes cool enough to preserve ice-fields)?? Are the risks of doing nothing and allowing mean global temperatures to rise high enough to cause massive methane outpourings from the Siberian Tundra, to cause the Greenland and West Antarctica Ice-sheets to disintegrate raising sea-levels by over 10 metres worse than risking some [unintended] consequences of carefully planned operation to halt global temperature rise?? I am assuming that we in the West do all we can to reduce CO2 emissions and to lean on emerging markets as much as possible to do the same in the interim and we still fail (in fifty years' time- by which time things will start getting serious) to get global CO2 emissions to half what they are now. If that's the case do we just continue trying to get the global community to respond and do nothing else except continue to have summits (Brasilia in 2030, Chennai in 2045, the Harare Cool Earth Summit in 2064, perhaps!) in which the world's Government continue their hand-wringing saying "Something Must Be Done To Save Earth!" without any collective willingness to commit to specific measures? Lets get all the brains together to see what if, this comes to pass, we should do. You might think that we should not to anything but adapt to a much warmer Earth with most of England getting a climate more akin to the hills of NW Portugal today. Plans for evacuating London, Newcastle, Liverpool; getting all British homes equipped with air-conditioning to cope with long periods in July and August with a humid 35C and to take in refugees from much of Africa that will simply become too torrid for human civilizations anyone?? I do not think that this situation arising is far-fetched because the specific measures that Western and fast-developing economies would require to get them carbon-neutral in fifty years will be totally unacceptable to large percentages of their respective electorates and such policies would plunge the economies concerned into recession: In other words their governments will cave in and refuse to implement the necessary policies unless of course they are dictatorships like Mao tse Tung or Robert Mugabe, or the governing parties want to be voted out of office for good! On the other hand we do, in my view, have a little more time than most models suggest because natural variations in the Sun's output predicted to occur over the next 30 years (a number of solar physicists believe the Sun is about to enter a quiet Maunder-Minimum type phase during which its output drops by up to 0.5%). Other factors such as worldwide man-made aerosol pollution from fast-developing countries like China, Brazil and South Africa will slow down the rate that rising CO2 levels leads to higher global temperatures. But developing countries will learn to clean up their smoke-stacks in time and the Sun will increase in strength to current levels (or more) after 2060 so complacency will be costly.

I wonder what the possibilities are for going there for a special Ultra Cold Holiday in mid-February: I know that there are flights to Greenland via Denmark, but getting to Summit to be in amongst some of this exciting weather (-50C and views of the aurora across the ice-sheet) might be a bit tricky. Sure beats a trip to Scotland or to the Alps at the moment where there is not much snow let alone far-below-zero temperatures!

Unfortunately the good cold snap does not look very likely. Predictions of a Sudden Stratospheric Warming high over the Arctic leading to blocking highs and a spell of severe wintry weather from Russia in January (see long term prediction for winter 2015/16) are looking hollow. The BBC long-term outlook has (in the main) continued westerlies and mild wet weather (even if less mild than recently). They were predicting snow on high ground in the North and Scotland by today, and I look out of my house at 400 metres above sea level near Alston (North Pennines) and see rain and hill-fog along with a temperature of 4C at 10 AM. There is to be a short cold snap later this week but its a moot point as to weather it materialises into much- the next depression in the North Atlantic is likely to replace the SE winds of the last few days with westerlies and (looking at the weather maps) we have to wait until Sunday before northerlies set in for a couple of days (even they may not materialise, the prediction for a few days ago had easterlies over us with low-pressure in the English Channel!). My take is that the jet-stream and higher-latitude Westerlies (caused by El-Nino and the westerlies of the QBO high over the Equator, along with the constant need for Westerlies in higher latitudes to counterbalance the effect of tropical, subtropical and Polar Easterlies [to stop the Earth slowing down in its rotation- and the Westerlies need to be stronger if they are in higher latitudes close to the axis of the Earth's rotation to achieve this], all this will see to it that the Atlantic influence with mild, rainy south-westerly and westerly winds wins out for the remainder of the winter (on the whole).

Even here at Nenthead in the North Pennines its just been raining albeit chilly at 4C with a south-easterly wind. These "globally-warmed" mild rainy winters do me in!! It would be lovely to have a return to something like we used to get in the early 1980s when the temperature would drop to -5C with a biting east wind and a foot of snow would fall (with drifts several times that), then after that the skies clear with winds falling light and a starry night down to -12C occurs! We used to get such conditions in winter quite regularly and it was interesting when it happened- roads blocked, cars freezing up so we could never get to school!

A further point about using trees in the fight against Global Warming, particularly at higher latitudes is that it all depends on the type of trees used: Deciduous trees have advantages over conifers in that they are not dark green all year-round. Indeed certain North American trees produce bright yellow leaves which could increase the trees albedo to over 30%; others produce brilliant white blossoms in spring that similarly increase albedos at a time when the Sun is getting strong in higher latitudes. However, a forest of bare trees in winter still absorbs more of the Sun's heat than bare ground and the effect is enhanced with a highly-reflective snow-cover that the wind blows off the trees. Trees are still evapo-transpirating (and have dark green leaves) in October if the autumn is mild in many mid-latitude locations- the net effect with the Sun weaker by then is for increased cloud to have more of a warming effect through keeping in heat that would otherwise be lost to space under clear skies during long autumn nights. On balance, I would concur that new forests planted north of about 50N would have a slight global warming effect; the same would be true if forests could be established in barren deserts like the Sahara where both the loss of surface albedo and greatly reduced radiative heat loss (due to clear dry skies being moistened and clouds being produced) caused by forests would outweigh the effect of extra CO2 uptake. Anywhere outside deserts between 50N and 50S increased forestation would have a cooling effect overall so forests should be planted in these areas.

Governments around the World certainly need to realise the gravity of the situation before it is too late: I was discussing with my brother the merits of planting trees on a grand, grand scale yesterday and I have to say that there is certainly something in this. Trees absorb large quantities of CO2 from the atmosphere and (over time) they could prevent CO2 levels rising to the point whereby this causes dangerous levels of global warming occur. My brother also pointed out that lots of healthy young trees would use vast amounts of energy from the Sun in their growth and that, in turning CO2 into oxygen and carbon trees cause an endothermic reaction in that heat (and light) from the Sun is used, and it is used to make chlorophyll. Certainly trees on a large scale would absorb CO2 from the atmosphere and contribute to a small reduction in the net heat input into the Earth-atmosphere system. However, trees are dark; certainly those in the jungles and conifers and deciduous trees in summer in mid-latitudes have albedos less than 10%- so surely replacing relatively pale open grassland and scrub (albedo 20 to 25%) with dark forests would increase the proportion of heat absorbed from the Sun contributing to a warming that would cancel out most of the supposed-cooling effects (reduced CO2 over time and endothermic reactions). Alas, trees also moisten the atmosphere above them through evapo-transpiration and promote higher rainfall (this undoubtedly helps the trees planted in drier locations) and the more frequent cloud-cover over newly-forested areas would result in more of the Sun's energy being reflected (cancelling out the effect of darker trees compared to bare ground). Trees are only evapo-transpirating in summer in higher latitudes and throughout the year only in the deep tropics, at times and places where increased cloud-cover reflects away strong sunshine and where this effect is greater than the effect of cloud-cover having a warming effect at night through preventing outgoing long-wave radiation. Certainly, there is a case to be made for promoting the planting of trees on a vast scale in regions like southern Brazil, sub-Saharan Africa and parts of the Arabian Peninsula where summer rainfall is marginal. Forests in these locations would probably have a net cooling effect (at least over the longer term) and evaporation from the trees could promote rainfall in these areas, stimulate crop yields and give a boost to local economies all at once. Replanting higher-latitude forests where the Sun (overall) is weaker and where the increased cloud-cover that results is more important at preventing net radiative heat-loss at night than reflecting heat from a weaker Sun is not something I would particularly advise in the fight against Global Warming!

Since the pollution of the atmosphere with sulphates and aerosols through industrial activity has had a cooling effect that negates some of the impact of rising CO2 levels; might it not be a good idea to actually ALLOW industries across the World to pump as much sulphur and aerosols into the atmosphere as possible? It would delay the arrival of the point of dangerous levels of global warming when mean global temperatures are more than 2C above pre-industrial mean temperatures and (in so doing) it would buy more time- maybe 10 to 15 years- for countries to switch to very low/zero-carbon economies. People in cities could be issued with pollution masks (and/ or we could invest in huge long pipes that lead up to the stratosphere and held aloft by helium balloons that could suck the aerosol/sulphate pollution into the stratosphere where it has more effect on keeping the Earth cooler).

My take on the COP21 in Paris was that it was a formalised promise of 148 countries together promising to make their countries carbon-neutral by 2050 but without needing to commit to any specific measures in order to achieve it: The measures required, massive taxes on oil and gas consumption/production in order to fund green and renewable energy alternatives, closing power stations and having rolling-black-outs- no government will get this past their respective electorates!! In practical terms, the only way we can prevent global temperatures rising above the 2C above pre-Industrial threshold is a) more R & D into the means of directly removing CO2 from the atmosphere and b) Geoengineering Solutions. It is going to require a collective commitment to really go on the offensive against Global Warming with resources that require international cooperation (yes, there are risks and side-effects but none as bad as letting temperatures rise out of control) to have a real hope of preventing dangerous levels of warming. Having said that, I do think the Sun entering a Maunder Minimum phase lasting 30-plus years (during which solar physicists predict its output will drop by 0.5% or more) will buy us time from circa 2020 to 2060 but in fifty years' time the mean Solar Constant will return to normal and if governments are still wringing their hands with CO2 levels upwards of 550 ppm (as seems most likely to happen) we will all be in big trouble if nothing else (aside trying to brow-beat governments into imposing recession on their economies- they wont!) is done.

Firstly, Happy new Year. It is a radical suggestion and I have to say a bit tongue-in-cheek to advocate provoking the arrival of a new Ice Age to stop global warming! However I do think Geoenginneering should be considered seriously, and practical measures enacted for keeping the World cool as CO2 levels rise inexorably as governments around the World wring their hands because their respective electorates refuse to accept the implications of 80% emissions cuts. The consequences in terms of severe summer heatwaves, coastal flooding and rising sea-levels of global temperatures rising more than 2C above pre-industrial averages justifies, in my view, researching into practical measures to limit global temperature increases. It is true that there are possible side-effects but are the side-effects (overall) going to be as bad as what could happen should mean temperatures be allowed to rise too much? Take my suggestion of allowing industries across the World to dirty the air with sulphate/aerosol pollution: The worst that happens is that a few million people get chest ailments (for which there are remedies) and acid rain kills off some forests in Scandianavia; but we prevent killer heatwaves that make life unbearable for millions in Europe and rising sea-levels that could mean forced abandonment of the East End of London and much of East Anglia with many other countries being affected by similar displacement whilst large numbers of plants and animal species are displaced/killed off. This is the sort of trade-off we need to look at. Or a couple of powerful H-bombs exploded on a remote tropical island in the Pacific (after evacuating any locals) putting so much dust into the stratosphere we cool the Earth and buy time to invest in and build a carbon-neutral economy- a few animals on the said-island might die but that is as nothing as to the massive displacement/loss of species and the misery of long 30C-plus summers across northern Europe that could occur if global warming continues unchecked. I do not downplay that there are (undoubtedly) risks with Geoengineering measures, there are bigger risks in allowing governments (fearful of their voters) to continue permitting their countries to ply the atmosphere with much more carbon-dioxide. The COP21 event in Paris did not produce agreement to specific measures to reduce CO2 levels on the scale that will be needed, no government in the World is willingly going to impose steep tariffs on businesses and inhabitants and put their economies into recession because they would be voted out of office for good! Helping countries to adjust to a zero-carbon economy will (therefore) take time and it will be a century or more before this is done; it means that if nothing else is done to combat global warming it will become too late to reverse the effects of dangerous global warming before we get to that point! I would even assert, in view of all this, that if we cannot get international agreement on implementing Geoengineering solutions, that there should be a "Coalition of the Willing" (of say, USA, Canada, Britain, Scandinavia, Germany) to go it alone and drop a few mighty H-bombs on the remote tropical island in the Pacific (or blast an Arctic mountain at noon in June with an asteroid- to reduce the tilt of the Earth and weaken the Summer Sun in the Arctic and preserve the ice-cover there) in order to arrest a dangerous change in the global climate.

Indeed, nice to see that the Greenland Icecap is still very cold. I sometimes check the data from the AWS at Summit, almost 3000 metres up on the Greenland Icecap and air temperatures below -50C are commonplace from November through March; minima down to -60C occur in most winters. Summit, Greenland has to be the new "Cold Pole" since Verkhoyansk and Omyakron in NE Siberia struggle to get below -55C in most years (possibly related to global warming and a weaker Siberian High in winter- with the Ferrel Westerlies pushing along the North Russian Coast, this never used to happen in winter during the 1970s and early 1980s).

There is, of course, means of removing the threat rising sea-levels and dangerous global warming on a permanent basis by deliberately starting the next Ice Age. Man has the resources and technology today to do this in one fell swoop and it can be done without wiping out large numbers of species or people: I discussed in (3) (above) the "Kidnapping" and steering an asteroid into the Earth, we would need to find one somewhat larger and take up masses of hydrogen fuel with a big rocket into space, find an asteroid about 10 miles across and attach the powerful rocket to it. With very powerful jet-engines we could steer this asteroid to hit one of the trans-antarctic mountains from the north at a speed of over 50,000 mph (angling in at about 45 degrees) at 4 pm local time in late-October. This would do two important things on a long-term basis. 1) It would push the Earth into an orbit slightly further from the Sun so that the Solar constant is (on average) about 0.5% less. 2) It would reduce the summer tilt of the Earth from 23.5 degrees to about 20 degrees by 2100 This would reduce the strength of the Summer Sun at high latitudes and ensure that rising CO2 levels did not lead to melting ice. On the contrary the drop off in insolation near the poles would be substantial due to the Sun's rays glancing off the surface and having to pass through a greater length of atmosphere before reaching the surface, the result is likely to be increasing snow and ice in high latitudes so that more of the Sun's heat is reflected. On the other hand winters would not be so continually dark over Siberia and northern Canada though there the winter Sun would still be so low as to make no real difference to the winter heat budget- the net effect would be a sharp negative change in the annual radiation budget at higher latitudes causing snow and ice to spread rather than decline. The third effect would be to pulverise the trans-antarctic mountain hit and cause volcanoes that (together)would throw up so much dust into the atmosphere globally that the amount of solar radiation reaching the surface declines by up to 5% globally over the first decade after it happens. This is enough to cause substantial global cooling leading to big increases in snow and ice cover at higher latitudes. By the time the dust and volcanic ash settles the weaker spring and summer sunshine at higher latitudes (caused by decreasing the Earth's tilt) would ensure the snow and ice stays- permanently as the snow/ice cover would reflect 80% of the weaker Sun's heat back into space. Nobody, of course lives (and precious few insects) live in the Trans-antarctic mountains so the vast asteroid would not kill anyone itself. Volcanoes are part of nature and we can get those living close to them to evacuate for a few days until we are sure that they wont erupt as a result of the asteroid collision (if this does happen, the people would be out of the way at the time). The only real moot-point is whether we would want to cause an Ice Age to stop Global Warming once and for all. There are a number of reasons why it might be preferable over global warming: 1) Tropical locations change little in temperature and tropical countries may have more land as the sea recedes. 2) Drought is a real threat to the tropics in an Ice Age (particularly if the tilt of the Earth is reduced lessening monsoons in so doing), but we can help them adapt with investment into water desalination units. However the Equator is likely to stay wet. Less sticky moisture around means that many in the tropics escape the effects of bugs and water-borne diseases and slightly cooler conditions for many would be a welcome alternative to the heat. 3) Large amounts of snow and ice at higher latitudes provide an ideal source of freshwater for higher latitudes. Very severe winters down to -50C would kill the bugs that bring pestilence and disease for folk in northern countries. Big greenhouses could be erected so that fresh vegetables can be grown in summer and homes could be triple-glazed so that folk can stay warm. The snow and ice would add to the beauty of the countryside in Britain, North America and across Europe and we could have a thriving skiing/glacier-based tourist industry for all northern countries. No-one would have to contend with floods or sticky summer heatwaves anymore as the climates would be too cold and dry for that. 4) It is true that large amounts of species would die or be displaced in an Ice Age (the same is true if Global Warming gets out of hand!). In Britain with the North Sea and Norwegian Sea freezing over we could have wolves, reindeer and polar bears paying a visit. 5) Some northern cities could get buried in ice but extra land would become available as sea-levels dropped. In any case cities like Newcastle and Aberdeen could prevent themselves becoming entombed in the new ice-sheets by spreading salt in vast quantities over the urban areas and using snow-clearing equipment to remove snow and ice from those areas in summer so that they are not overwhelmed the following winter (when salt would prove useless in temperatures below -40C). Northern city-dwellers would always have pristine gleaming-white countryside on their doorsteps, get in their snow-buggies and visit it in any season! If they are adventurous they could visit the new Grampian Glacier or North Pennine ice-sheets! Breathtaking!

@cowdog Firstly, I hope you have had a good Christmas and all the best for 2016. Of course all serious geo-engineering solutions are unproven in that they have not been done before. I do also think the global community does have a little more time to come up with well-researched measures with minimal side effects to counteract Global Warming because the Sun is predicted by a good number of Solar Physicists to enter a Maunder Minimum phase lasting from 2020 to 2060 when the Solar Constant will drop by 0.5% or more and sunspot activity will be very minimal. However, it is conceivable that solar physicists are wrong about the predicted Grand Solar Minimum; it is impossible to send probes to investigate the interior workings of the Sun (which is over 1 million degrees C) without their being destroyed and the predictions are based on little more than observing past Sunspot Cycles- so we could all be horribly surprised. To that end the global community should stop wringing its hands; this Paris Summit was a commitment to keep global temperatures from rising over 2C above pre-industrial levels and this is only practically achievable by cutting CO2 emissions globally by 80%: Realistically this is only absolutely achievable by decimating the global economy and condemning billions to penury through high "green taxes" to pay for more windmills, solar panels, geothermal energy, investing in "electric cars" and so forth. I am not saying that R & D should not be poured into green energy sources but to reduce CO2 emissions globally by 80% by 2020 would cost ££ trillions and decimate industries and cause millions of job-losses. Governments around the world would come up against their respective electorates very quickly and be forced to change track- this is neither realistic or practical! We are then likely to be left in a situation (certainly by the 2060s, possibly rather sooner if the new Grand Solar Minima fails to materialise or is weaker than predicted) where Governments are left wringing their hands in despair as global temperatures increase above the "2C warmer than pre-industrial" threshold and severe summer droughts and killer-heatwaves hit Europe, Russia and North America whilst rising sea-levels swamp London and New York as Greenland's ice melts away in large quantities. We have to look at other measures to bring global temperatures down from dangerous levels, I would assert the risks of doing nothing are much greater. Painting cities white, allowing aerosol pollution don't require major global collaboration of resources and technology, just some changes in legislation as much as anything but doing nothing is not really going to be an option as the years pass.

I have posted (in the past) some other ideas such as dusting snow-free tropical mountains with salt to they reflect the Sun's heat, damming the far North Atlantic with floatable plastic bridges to stop the warm waters of the North Atlantic Drift reaching the Arctic and assisting ice-melt and pumping sulphur dioxide into the stratosphere to reflect more of the Sun's heat. All of these, it must be said, would be very costly and would need to be redone regularly, there would be side-effects (sulphur dioxide in the stratosphere could lead to acid rain a few years down the line) so one would need to concentrate on measures that could be done once then (hopefully) need never be done again. A much more practical measure (which countries could be strong-armed into passing into law) is for global legislation requiring that all new-build and existing urban surfaces be made of white stones or be painted white- that means all roads, buildings, rooves, car-parks, airports, bridges and motorways. Sure it would take adjusting to (folk will need to wear dark glasses) but if we add up to all urban areas globally we could cut 1% off the heat absorbed from the Sun- buying 30 years of time to gain low-carbon sources of energy. Farmers could be incentivized to maintain 10% of their land in a brilliant white state by spraying a water-resistant chalk solution (or lime) onto their land three times each year. For sure there is the cost of the paint (and yes, CO2 would be produced in its manufacture, transport and application) but brilliant white paint on a surface would repay its carbon footprint several times over! Dust and urban pollution are natural products of the global economy, China and India are good at producing this in vast quantities; Britain, the USA and most European countries were heavy polluters in this regard in the 1950s and 1960s- elderly Londoners will recall the infamous smogs that sometimes afflicted the capital. However, in passing various Clean Air Acts enforcing companies in the West to clean up their smokestacks the resultant clean air means we have lost a vital buffer against Global Warming as more of the Sun's heat gets through to the surface. The effect of pollution in the atmosphere when and where the sun is lower in the sky as the Sun's rays pass through a greater length of the atmosphere, thus the loss of man-made aerosol puts Arctic ice and winter/early spring snow-cover over Russia and North America at considerable risk. We might not like a return to the days when we were choking in smog but we should repeal Clean Air Acts (governments around the World should be strong-armed into doing likewise!) and encourage all factories and homes to put as much smoky pollution of the sun-blocking kind as they like!! The extra aerosol in the atmosphere will knock 0.5C off global temperatures buying another twenty years of time to invest in energy that is not only smoke-free once more but also free of the gaseous pollution of the sort that helps raise (rather than reduce) global temperatures: In the meantime city-dwellers should be encouraged to buy masks like they wear in some Chinese cities!

On a serious note, do we dismiss all ideas of geo-engineering because there are inherent risks in them? This climate summit in Paris was full of vague commitments by 148 countries to reduce CO2 emissions and "limit" global temperature rises to 2C by aiming for 1.5C warming above pre-industrial temperatures. CO2 levels have now reached 400 ppm whereas in the 19th Century CO2 averaged 260 ppm, the climate is still adjusting to equilibrium and a doubling of CO2 from industrial levels (to 540 ppm) plus likely effects from methane being added to the atmosphere causes an initial forcing of 8 Watts per square metre. From Stefan's Law this is a warming of 1.5C (given the Earth is in balance with Solar input absorbed and radiative heat loss each at about 240 W/m-2) but add in the feedbacks from increased water-vapour trapping more heat and reduced snow cover (both seasonal and permanent) reflecting less heat from the Sun then the warming for doubled CO2 plus methane from pre-industrial times is 2.5 to 3C (there is some negative feedback due increased atmospheric convection and more global cloud-cover having an overall surface cooling effect). Global temperatures are already 1C above pre-industrial times, yet the atmosphere is still adjusting to higher CO2 levels today. It is however, my contention that the Sun is about to enter a Maunder Minimum phase lasting 30 to 40 years, during which Solar output will drop by 0.5 to 1%. This forcing will counter the effect of rising CO2 levels for a time and will lead to a slight global cooling lasting about 20 years. This will buy some time but not a lot of it. Thereafter however, further rises in CO2 levels combined with rising solar output will cause a sharp spike upwards in global temperatures by circa 2060. It means that governments across the World as a whole have forty years, at most, to prevent CO2 levels exceeding 500 ppm above which global temperatures will be destined to rise over 2C above pre-industrial levels: It is above a mean global temperature of 17C that the Greenland Icecap will melt catastrophically, that deadly killer heatwaves will become common in Europe and North America, that sea-levels will start rising rapidly causing the loss of big cities like London and New York to the sea, that severe drought and savage summer heat will make Mediterranean lands unsuitable for either agriculture, tourism or human habitation. Yet the measures required by governments around the World to cut emissions to prevent this happening (80% reductions in CO2 levels) mean such severe restrictions on using coal, oil and gas (and such taxes put on such pollution) that it would condemn billions of folk to poverty and cause a global recession. This is neither an electorally practical or realistic option. So we have to look at other measures of actively preventing global rises in temperature using man's technological means. None of the measures listed below are without risk but they are all relatively cheap and practical, and if any cause human death or species loss they are as nothing as to what would happen if we allow Global Warming to get out of hand: These measures include. 1) Exploding a couple of powerful H-bombs on a remote tropical island in the middle of the Pacific (after evacuating it). The massive ash cloud and dust raised would reach the mid-stratosphere and cut the solar energy reaching the surface globally by 2% for a few years (the Nuclear Winter is a much more serious extent of this happening). This would buy time, possibly a decade or more for humankind to develop a proper low/zero carbon economy on a global scale. The drawback is of course the radiation fallout but this significant fallout would be thousands of miles from any big population centres and it would only affect species on the island concerned. Don't forget the Russians tested their H-bombs in the Pacific in the 1950s and 1960s without discernible impacts anywhere else in the World. 2) Firing tens of thousands of very powerful rockets into space towards the midday Sun in June from an Arctic mountain. The combined recoil force would nudge the Earth's tilt towards 23 degrees then 22.5 degrees (i.e to make it less) over a hundred years. The effect would be to reduce the strength of the 24-hour Summer Sun over the Arctic (and Antarctic in its summer) so the snow and ice does not melt and continues to reflect the sun's heat thereby keeping the Earth cooler. Drawback- a lot of rockets would be needed to have an impact on the tilt of planet Earth which is a very massive body and outer space would become littered with lots more spent-rockets. This is also likely to cost much more than option 1, but it is a means of achieving less global warming without any ecological side-effects. 3) "Kidnapping" an asteroid in Space and steering it so that it collides with a similar remote tropical island in the Pacific Ocean as (1): Best if this can be done with the asteroid blasting down in a north-westerly direction mid-afternoon (local time) in April to both reduce the summer tilt of the Earth and push the Earth into an orbit slightly further from the Sun,- both these effects would bring about changes to the tilt of the Earth and strength of the Summer Sun that would help preserve highly-reflective snow and ice-cover. Vast amounts of dust would be blasted into the stratosphere where it would help reduce the intensity of the Sun at the surface a further 2%. There would not be problems with radiation fallout but the said tropical island would be obliterated by the impact and this would be very expensive. But if we can get Tim Peake to the International Space Station we can work on getting a big rocket (with fuel) to an asteroid a mile across and then steering it into the Earth; it is achievable albeit at considerable cost and with considerable technological resources. I think it is doable if R & D of ££ billions is put into it over a few years! Certainly governments around the World should be directing 0.1% (or more) of GDP into research and development of ideas to combat global warming.

It is my take that there wont be any SSW event over the high-Arctic this winter: The Circumpolar Vortex is extremely strong and it is overall north of its usual position. The Law of Conservation of Angular Momentum (westerlies need to blow stronger to counteract tropical and polar easterlies if they are in higher latitudes) dictates the Westerlies are likely to be too strong and too far north for pronounced troughs and ridges (with ridges combined with stronger winds hitting the Himalayas that are a pre-cursor to SSW's developing since the upper-ridge is "pushed" up into the Arctic): Cold weather is likely to come from the North West later in the winter due to cold water in the mid-north Atlantic and Arctic ice being further south than usual off Canada- modest upper troughs (nothing excessive) in the Upper Westerlies will be displaced eastwards towards northern Britain as a result. Because of this likely development, in my view, I do not buy into the idea of a quiet end to the winter though February will probably be the coldest month of the winter (though less wet than December or January it will still be wetter than usual).

Dear Weather Enthusuiasts; First of all "Happy Christmas" and all the best for 2016. I am sorry to say that I have not produced a winter forecast for 2015/16; some of you appreciated the forecasts I produced for 2013/14 and 2014/15 but I have unfortunately not had much spare time over recent months so I have not had so much chance to visit this Forum, let alone produce a detailed forecast for the winter. I have been working as a full-time commis chef and also studying NVQ Level 2 Accounting; I also produce and send monthly weather reports to the local BBC news (Look North for me near Alston, Cumbria) so I have my hands rather full. This is why I have not actually produced a detailed weather forecast for this winter. My predictions for the winter would have led me to conclude a mild and stormy season overall, though not with the record amounts of rain we have seen (leading to record flooding across large parts of the North and ruining hundreds of Christmases!); January 2016 is likely to continue mild and stormy (possibly some snow at times in Scotland). There will be more short snowy snaps with sharp frost due to Arctic airstreams at times during February; interspersed with further milder wetter spells with strong south-westerly winds. The El-Nino in the Equatorial Pacific is a record strong one and the QBO (Quasi-Biennial Oscillation) of winds in the equatorial stratosphere is in a westerly phase at the end of 2015; both these factors are supportive of mild stormy winter conditions across northern Britain. The Sunspot Cycle remains in active phase (as it has been since 2012 and likely to remain so through much of 2016), the interactions from solar flares and interactions with the Earth's magnetic field are supportive too, of strong winter westerlies at higher latitudes. The Arctic ice-cover is near average extent in the Canadian Arctic but retreated north of its seasonal position in the Eurasian Arctic- this encourages the westerlies to blow further north and (to satisfy Conservation of Angular Momentum laws) to thus blow stronger. However, as with last year, there remains a sizeable patch of the mid-North Atlantic close to 45N with colder-than-normal waters and with sea-ice west of Greenland further south than usual this is likely to (by February) with sea-ice even further south in that sector to lead to high-pressure in that region at times with surges of cold Arctic air sweeping south along the eastern flank. Such cold air will reach Britain at times following the passage of some of the (likely) deep depressions we have been getting lots of lately. I am not at all convinced by the forecast for the latter part of the winter produced by Ed O'Toole and Tony Wells; for Sudden Stratospheric Warming (SST) to occur over the high-arctic there needs to be some predisposition towards weaker mid-latitude jet-streams that will allow upper ridges of warm air to buckle far to the north and most such SSTs it seems there is a pre-requisite for strong upper westerlies to impact hard on the Himalayas or high Pamirs of central southern Asia so that the fast-flowing air is forced upwards over great heights leading to ridges extending north over Siberia and into the Arctic. Currently the Cuircumpolar Vortex is blowing too strongly and too far north for these developments to unfold. It is thus my assertion that there will be plenty strong winds and rainfall in January and February 2016 as well, particularly for the North West and Scotland (sorry for folk living in Cumbria and Lancashire) and that cold snaps will come from the north-west (off the Greenland Icecap) in February consequent on colder-than-usual conditions in the mid North Atlantic and Canadian Arctic that, after another month of the prevailing NW winds that have been blowing there this winter, will be especially cold: This, combined with the prevailing SW winds over much of northern Europe until then, will shift the trough in the upper Westerlies east towards the UK and that development is likely to bring about cold snaps. However, the North Atlantic will have cooled down significantly by early February so with less moisture evaporated from the colder ocean surface there should be rather less rain than of late. Ian

Another possible solution to mitigating global warming could be the painting of all mountains that never get snow but that are sparsely populated brilliant white: International legislation could be passed to this effect and special white paint (or perhaps refined salt) could be sprayed onto barren mountains each year to keep their albedos above 60%! Only there is a drawback; how much CO2 would be released in sourcing the materials for (and manufacturing) the paint or refined salt needed to maintain all barren mountains in a white state?

@ Dr Astro And given the higher concentration of AWS over the country (England is now well-covered), the right conditions could see -30C recorded in a Stevenson Screen somewhere in England (for example, Redesdale Camp near Otterburn, Northumberland records surprisingly frigid temperatures given the right condiions): All it takes is for three or four days with strong east or NE winds direct from Siberia caused by low-pressure over the Channel extending to central Europe (with high-pressure from NW Russia to Norway), the effects of the low-pressure and passage of frigid air over the relatively warm North Sea gives widespread deep, powdery snowcover. All that is then needed is for a strong ridge to extend from the Scandinavian High right across the UK so that dry, clear skies and calm conditions over the snowcover (combined with the frigid atmosphere) permit strong radiative heat loss and a rapid fall in temperatures from already very low levels. Even if there is 1 to 2C global warming from current global temperatures over the next 50 years we cannot be certain this sequence of events in mid-winter will never occur in all of the next fifty winters! As Britain's network of weather stations increases it is indeed possible that such extremes will be recorded (maybe in the bottom of an upland valley in North Yorkshire, perhaps somewhere like Swaledale or Wharfedale).

@ John Baldrick The cold "north-westerly" snaps seem to be somewhat longer and more entrenched through late January and Arctic airstreams are set to remain into the first week of February. That said, I am encouraged that the basic forecast for January 2015 (at least for the North Pennines)- stormy, wet and with a cold snap later in the month has come to pass, even though the "cold snaps" (there were two, not one) have been longer in duration than I predicted (leading to mean temperatures near-normal rather than a degree above). On a more serious note, a look at the weather maps for Europe/the North Atlantic seems to indicate some weakening in the overall strength of the higher-latitude Westerlies coming into NW Europe going into February. The weather chart today shows no depression deeper than 970 mb in the sub-arctic and there is a ridge extending from Iceland to the Azores; this means a more north to south airflow with Arctic air reaching most of the UK. The weather at Nenthead (the village near where I live) has become very cold with a number of days not exceeding freezing point and I recorded -6C last night. We also have over eight inches of snow lying (it was ten the other day). In the light of recent developments I would shave a couple of degrees' Celcius off the February 2015 mean temperature prediction and assert that there will be more than a couple of short cold snaps from the north-west: Northerlies are likely over the next couple of days and I would assert that at least one more "direct hit" from the Arctic (at its coldest in February) will occur before the month's end. This means daytime temperatures near freezing point (with snow-showers) even in the South and hard night frosts in the clear night skies following these cold snaps. That aside I still think mild, strong west/SW winds (with high rainfall but further snow on high ground in Scotland and the North) will dominate in between so this means near-average February temperatues for the South but fractionally colder than normal for Scotland and the North (i.e. mean daily temperature about 3C in the lowlands of Scotland). It will still be substantially wetter (and windier) than normal over most of the country (the SE of England being the possible exception where near-normal rainfall is likely and with a little more sunshine than the February norm). The sea-surface temperatures over the North Atlantic and temperature regimes over both Greenland/Canada and NE Europe do not suggest anything other than continued strong westerly/northwesterly airstreams for February as a whole. The patch of seasonally colder-than-normal waters in the mid North Atlantic near 45N is sufficient in intensity to put high-pressure there and encourage an anomalous north-westerly flow for points further to the north-east; this does not, in itself, point to a change to prolonged blocking in high-latitudes with frigid northeasterlies for the remainder of the winter. Ian