I don’t know much about climate change, I believe it, however, I was alarmed by this map about how large swathes of the world would be left uninhabitable due to a runaway greenhouse effect.
Is this map an accurate prediction of what could happen in the next couple of decades? I still can’t wrap my head around it, Japan largely abandoned along with China and the US?
Is it scaremongering? I can’t imagine those governments or their respective populations just deciding ‘Yup, we can’t do anything now, let’s go to Canada’
Seems that the map came from a British report from 2009, AFAIK it was based on early projections that are a bit obsolete now. The map projects the temperatures between 2060 and 2100 if present rates of adding CO2 and other global warming gases into the atmosphere are not slowed.
Yes, that map is undoubtedly realistic for a 4C average global rise in temperatures. All that’s uncertain is how long it will be before that number is reached.
Global warming is also undoubtedly the most important and pressing issue of our time. If scaremongering creates even a slight change in attitude or postpones these results for an extra couple of decades I’m all for it.
A more recent study shows that the changes will take place more on higher latitudes:
So, if we get to see no stronger control of our emissions, it is a matter of time that we could see an increase of more than 2 degrees Celsius on equatorial regions (Remember, Celsius degrees increase at a higher rate than Fahrenheit ones) all over the world, while higher latitudes can see 4 or more degrees Celsius of an increase.
Part of the problem with a map like that is that regional projections are really hard to do reliably, though we’re now getting global circulation models with much finer spatial resolution. One thing that can be said reliably, though, is that 4°C temperature rise relative to some nominal 20th century average would have pretty devastating effects. The good news is that this kind of temperature rise by 2100 is unlikely because projections show it to be a worst-case outcome, essentially requiring reckless continued growth in global emissions. We’d hit that temperature by 2100 under conditions that allowed greenhouse gas accumulations to reach a net incremental forcing of +8.5 W/m[sup]2[/sup], a scenario called RCP 8.5. By contrast, RCP 6.0 or even 4.5 are considered more likely, but if we don’t reverse the trend of GHG accumulation we’re going to hit 4°C eventually and just keep right on going.
As I’ve often said, CO2 levels during glacial maxima have averaged around 180 ppm and during interglacial maxima between 280 and 300 ppm. It’s cycled in that narrow band for millions of years. Today it’s over 400 ppm.
Here is a brief chart of some of the expected impacts at different temperature levels relative to temperatures in the latter part of the 20th century. It’s from the older IPCC AR4 report but still reasonably accurate. This is a report on some of the RPC and temperature projections from the newer AR5. Unfortunately this brief report only shows RCP 2.6 and 8.5 on most of the charts and you sort of have to extrapolate the middle ones, but it gives you some idea. The full IPCC Working Group 1 AR5 report is excellent and informative reading if you’re interested. If you want something briefer, download the Summary for Policymakers (SPM) from that page.
Hell yeah go to Canada … well, maybe your great-grandchildren should go to Canada … it’s beautiful up there now and the future is nothing but prosperity and wealth … and you can trust Canadians to do the right thing …
The map you’ve linked to has a major red flag … it shows deserts along the equator … that’s pretty much physically impossible … here’s a diagram of the large scale circulation pattern on Earth, see the arrows all point up and the equator, that means it rains all the time, ask anyone who’s lived near the equator … 30 feet of rainfall every year doesn’t allow for a desert climate …
Emphasis mine
Oh, sorry … it’s completely unrealistic at any temperature … there’s never been a desert at the equator while conditions on Earth allow for rainfall … billions of years now …
I appreciate scaremongering for truly noble causes … but if the claim is so divorced from reality as to be complete fantasy, it’s going to cause minds to change the other way … many of us can simply drive a few hours south and experience the total sum of all climate change over the next 100 years in just an afternoon … have dinner and drive home and wonder what’s to be a afraid of …
The idea that 4°C would only result in 2 meters of sea level rise seems awfully optimistic. And all the displaced populations are going to peacefully migrate to compact, high-rise cities, with no wars or border walls or any of that trouble?
Looking around, that OP map is not coming from the Met Office. It seems to be coming from a book by Parag Khanna, an international relations expert, not a climatologist. So not as reliable as the other map I linked to. Better to look at the references that wolfpup made too.
That might be true, but I’d like to see cites. Weather patterns and climate changes are heavily dependent on the configuration of continents and oceans, though, and our present configuration seems to have potential for new patterns. See this study in Nature Climate Change that shows aridification in equatorial South America if not Africa.
That’s a meaningless argument in the bigger picture, however. People are denying any coming inconveniences at any temperature change. Realism has absolutely nothing to do with the political discussion. The idiots will seize on anything, true or false, to bolster their case. People won’t wake up until they feel it slapping their faces.
This is all basic meteorology … if you haven’t taken the class then my citation would be any textbook … not ground school, the textbook should be presenting triple integrals right away and systems of partial differential equations someplace … there’s good reasons for universities offering climatology degrees to start the climatology instruction at the junior level, you need two years calculus, a year of physics, a year of statistics and I’d recommend a year of general chemistry …
I only got as far as the first diagram in your citation, as this completely validates my claim … see in the “a” portion: Amazonia, The Congo and Indonesia are all noted as “humid” and the very highest of the index the authors defined … and in the “b” portion it shows these regions as “no change” … profuse rainfall today, profuse rainfall in a 100 years … this letter was written by climatologist for other climatologists, so we won’t find a detailed discussion of buoyancy forces … the authors assumed complete competence of such matters by the readers … and we can make all kinds a crazy claims by just ignoring 80% of the Earth’s surface, like the authors seems to have done …
“People won’t wake up until they feel it slapping their faces.” … you seem to be missing the time scales involved here … most babies born today will have lived their entire lives and died of old age before 100 years will have past … a 3ºC increase in 100 years means that over ten years we’re still within instrumentation error … there’s nothing to ‘wake up’ to, we’re discussing several generations from now …
We’re heading for a major crisis, that’s for sure … the way Western Europeans and Anglo-Americans are blowing through a thousand kW-hr of electricity every month is unsustainable if expanded to the other 5 billion people we have today … a 100 years from now we’ll have maybe 10 billion more people … I don’t think we can burn fossil fuels fast enough even if the supply were unlimited …
Anyway … physically impossible for there NOT to be a convergence zone over the equator … due to the fact the equator receives the most solar energy …just apply what you know of buoyancy forces …
Well, Alaska’s freaking HUGE and I believe could support a good chunk of mass lower 48 migration if it got all pretty and green most of the year. That’s assumes they throw some mega cities up there in preparation like they’ve done in China.
Interesting idea building in Antarctica. I could see the US commandeering that too.
I’ve never doubted global warming … but if pressure, relative humidity, precipitation rates and timing, and wind speed and direction do not change … then a few degrees increase in temperature does not change climate except for a few narrow bands … a place like St Louis will change from “humid continental” to “humid sub-tropical” … the catastrophe here is Missouri farmers will have a week or two longer growing season in 100 years, or just like Arkansas today …
Global warming won’t cause bad things to happen … that’s a philosophical position since science doesn’t define “good” and “bad” … if the climate model outputs “bad” as a result, then it was programmed to do so …
if ($climate_forcing > 1.5) {echo “bad”}
else {echo “still bad”}
Missed Edit window: I don’t disagree with Exapno Mapcase … just pointing out the vast majority of the Earth’s surface won’t see the index fall anymore than “noise” allows …
We had a similar conversation before, Of course this shows that you did not learn anything from Jennifer Frances and the other Polar experts that contrarians pointed before as being the beesnees; when in reality they were pointing out that the reduction of the winds actually leads to weather patterns getting stuck for longer periods of time, all that, and the loss of ice at the poles does change climate. Also the point made that while some wind circulation cells will slow down, others will increase in speed in a warming world.
This is false and total nonsense, absolutely fundamentally wrong. Most of the critical climate drivers do NOT remain stable under conditions of strong climate forcing and temperature rise – that’s fundamentally most of the basis for the concern about climate change! The most important things that change are regional and global atmosphere and ocean circulation patterns which make huge differences to regional climates.
A few degrees temperature rise will exacerbate global problems like increased damage from extreme weather, increased water stress, ocean acidification, 30% species extinction, sea level rise, total coral bleaching, and species range shift along with pests and disease vectors. Specifically in North America, the IPCC AR5 lists the following projections with high confidence – and that is in addition to global factors like casualties and property damage from extreme weather:
[ul]
[li]Wildfire-induced loss of ecosystem integrity, property loss, human morbidity, and mortality as a result of increased drying trend and temperature trend [/li][li]Heat-related human mortality [/li][li]Urban floods in riverine and coastal areas, inducing property and infrastructure damage; supply chain, ecosystem, and social system disruption; public health impacts; and water quality impairment, due to sea level rise, extreme precipitation, and cyclones[/li][/ul]
None of that sounds to me like “will not change climate” or “won’t cause bad things to happen” or “a philosophical position”. California wildfires are already at all-time record levels with smoke now visible on the other side of the continent.
Yes, that’s when I pointed out that that a reduction of winds means a reduction of power, so it is less likely for powerful events to occur, like longer drier droughts or hypercanes … so weather will be more moderated in a warmer world … less crop failures, less flooding, less human misery (my Bible says this last one is a “good” thing) …
If you want more extreme events, you’ll need faster winds …
None that you will accept? … fair enough … that’s allow in philosophy …
I clued into the first diagram because of the word “change” in the title of figure 1b … that has a very explicit definition in science … this displays rainfall changes with respect to aridity index changes … this is zero in the Amazon Basin … that means it doesn’t matter what the aridity index does, the effect on the Amazon Basin is nothing …
Scaremongering at it’s finest … take the most extreme forcing value humanly imaginable (= 8.5 W/m[sup]2[/sup], current value = 1.8 (±0.6) W/m[sup]2[/sup]) and show me a completely irrelevant shade of green and say that makes a horrific desert … I get it, don’t get me wrong … tell an Iowa corn farmer climate change he thinks no rain in summer … tell him global warming and he plans to work his fields a couple weeks sooner … 100 years from now has to sound scary or nobody will listen …
It appears that my earlier statement characterizing your claims as “false and total nonsense, absolutely fundamentally wrong” is a recurrent theme in your writing, because it applies here, too. This is totally wrong and exactly backwards, and reflects a fundamental misunderstanding of the research on Arctic amplification.
Increased radiative forcing means higher energies in the climate system, hence the predictions of stronger and more damaging storms and other damaging effects. For instance, the potential for stronger hurricanes because of higher sea surface temperatures imparting more energy to hurricane formation.
The work of Jennifer Francis and others pertains to expected reductions in high-altitude jet stream winds, leading to the above-noted extreme weather events lasting much longer, staying in one place for much longer periods and thereby being much more damaging. Cites:
We find robust relationships among seasonal and regional patterns of weaker poleward thickness gradients, weaker zonal upper-level winds, and a more meridional flow direction. These results suggest that as the Arctic continues to warm faster than elsewhere in response to rising greenhouse-gas concentrations, the frequency of extreme weather events caused by persistent jet-stream patterns will increase. http://iopscience.iop.org/article/10.1088/1748-9326/10/1/014005
The Arctic is warming twice as fast as the rest of the planet, an effect enhanced when the sea ice that normally cools the Arctic air melts away. Because of this, the air currents that come from that region are getting disproportionately warmer too, narrowing the temperature difference between the Arctic and southerly winds, and thereby weakening the jet stream itself. “The winds have weakened by 10 per cent over the past three decades in the west-to-east wind of the jet stream,” says Francis.
Francis thinks that, as the cool air of the Arctic becomes warmer, the jet stream is slowing down, almost to the point of stopping trapping weather systems in one place for prolonged periods. Instead of swirling round the world, winds reverberate back and forth in the same place, creating what she calls “extreme waves”.
… Between 1980 and 2010, extreme weather events doubled from about 400 to 800 a year, according to the insurance firm Munich RE.
