Sentences with phrase «meant by a positive feedback»

Explain what is meant by a positive feedback mechanism, using the example of when permafrost thaws.

Not exact matches

You seem to be the only one who doesn't understand his very clear explanation of what he means by it --(a) large enough positive feedback (s) that it (or they) exceeds the total amount of CO2 equivalent of all human ghg emissions.

However, while positive feedbacks are obviously necessary for such an effect, they do not by any means force that to happen.

The signals for positive feedbacks are beginning to be detected and measured but it is by no means clear yet that they are contributing strongly to GHG emissions and accumulation in the atmosphere.

Therefore, the rate of increases in CO2 and CO2e are by no means due only to positive feedbacks.

However, the contributions of water vapour / lapse rate and surface albedo feedbacks to sensitivity spread are non-negligible, particularly since their impact is reinforced by the mean model cloud feedback being positive and quite strong.

Peter Cox is the originator / author of the Triffid dynamic global vegetation model which was used to predict dieback of the Amazonian rain forest by 2050 and as a consequence a strong positive climate - carbon cycle feedback (i.e., an acceleration of global warming) with a resultant increase in global mean surface temperature by 8 deg.

To point out just a couple of things: — oceans warming slower (or cooling slower) than lands on long - time trends is absolutely normal, because water is more difficult both to warm or to cool (I mean, we require both a bigger heat flow and more time); at the contrary, I see as a non-sense theory (made by some serrist, but don't know who) that oceans are storing up heat, and that suddenly they will release such heat as a positive feedback: or the water warms than no heat can be considered ad «stored» (we have no phase change inside oceans, so no latent heat) or oceans begin to release heat but in the same time they have to cool (because they are losing heat); so, I don't feel strange that in last years land temperatures for some series (NCDC and GISS) can be heating up while oceans are slightly cooling, but I feel strange that they are heating up so much to reverse global trend from slightly negative / stable to slightly positive; but, in the end, all this is not an evidence that lands» warming is led by UHI (but, this effect, I would not exclude it from having a small part in temperature trends for some regional area, but just small); both because, as writtend, it is normal to have waters warming slower than lands, and because lands» temperatures are often measured in a not so precise way (despite they continue to give us a global uncertainity in TT values which is barely the instrumental's one)-- but, to point out, HadCRU and MSU of last years (I mean always 2002 - 2006) follow much better waters» temperatures trend; — metropolis and larger cities temperature trends actually show an increase in UHI effect, but I think the sites are few, and the covered area is very small worldwide, so the global effect is very poor (but it still can be sensible for regional effects); but I would not run out a small warming trend for airport measurements due mainly to three things: increasing jet planes traffic, enlarging airports (then more buildings and more asphalt — if you follow motor sports, or simply live in a town / city, you will know how easy they get very warmer than air during day, and how much it can slow night - time cooling) and overall having airports nearer to cities (if not becoming an area inside the city after some decade of hurban growth, e.g. Milan - Linate); — I found no point about UHI in towns and villages; you will tell me they are not large cities; but, in comparison with 20-40-60 years ago when they were «countryside», many small towns and villages have become part of larger hurban areas (at least in Europe and Asia) so examining just larger cities would not be enough in my opinion to get a full view of UHI effect (still remembering that it has a small global effect: we can say many matters are due to UHI instead of GW, maybe even that a small part of measured GW is due to UHI, and that GW measurements are not so precise to make us able to make good analisyses and predictions, but not that GW is due to UHI).

You add a forcing that should move the equilibrium by an amount x, but positive feedback means it moves, say, 2x to a new equilibrium position.

Positive feedback means runaway warming «One of the oft - cited predictions of potential warming is that a doubling of atmospheric carbon dioxide levels from pre-industrial levels — from 280 to 560 parts per million — would alone cause average global temperature to increase by about 1.2 °C.

This means that 67 % to 80 % of IPCC forecasted warming is not from greenhouse gas theory but this second theory that the Earth's climate is dominated by positive feedback.

That doesn't mean he's correct that atmospheric expansion caused by changes in solar activity is the primary positive feedback that drives climate change.

So, enjoined by a recent reCatcha to «ask mitely,» I will try at least one more time to ask if dashed line on graph # 3 in the recent Nature Geoscience article (by MacDougall, Avis and Weaver) on permafrost melt — taken together with the known fact that there are other carbon (and other) positive feedbacks — mean that, even if we stop all anthropogenic CO2 emissions next year, atmospheric CO2 levels will continue to rise indefinitely?