Scientists are moving beyond the "We can't say any one event is due to climate change" disclaimer to confirm what has become obvious. This week New Scientist is running a series of articles about climate change and how it is a factor that can no longer be ignored in the weather events we are experiencing. An editorial on July 9 put it succinctly; here's an excerpt.
IT HAS been yet another week of extraordinary weather. Torrential rainfall caused chaos across the UK. A record-breaking heatwave drifted across the US, broken by freak thunderstorms that left a trail of destruction from Chicago to Washington DC. Meanwhile, in India and Bangladesh more than 100 people were killed and half a million fled when the monsoon arrived with a vengeance.emphasis added. More below the Orange Omnilepticon.
We have become used to reports of extreme weather events playing down any connection with climate change. The refrain is usually along the lines of "you cannot attribute any single event to global warming". But increasingly this is no longer the case. The science of climate attribution - which makes causal connections between climate change and weather events - is advancing rapidly, and with it our understanding of what we can expect in years to come.
From killer heatwaves to destructive floods, the effects of global warming are becoming ever more obvious - and we ain't seen nothing yet. Our weather is not only becoming more extreme as a result of global warming, it is becoming even more extreme than climate scientists predicted.
Note: I've added several updates at the end of this diary to link to some really relevant info and graphics, plus one update linked to something I anticipated re recent studies suggesting the historical record on humans and warming may need another look.
The main article "How global warming is driving our weather wild" requires a free registration with a valid email address for access. It's generating a lot of activity at the New Scientist website. It's a long article for the magazine with a lot to say.
There is little doubt that things are going to get even worse. What is especially worrying, though, is that the rise in extremes can't be accounted for solely by the 0.8 °C warming so far. Events like the 2003 and 2010 heatwaves were projected to occur only after much greater warming, towards the end of this century. And while one or two freak events might be dismissed as simple bad luck, there have been suspiciously many of them in the past decade.The article looks at several factors that may be contributing to climate change and weather extremes that seem out of line for the small increase to date. For one, the amount of water plants put into the air depends on how much they have available. Normally this helps keep things cool - but when plants stop, it's like what happens if someone stops sweating. Temps start going up.
James Hansen at NASA's Goddard Institute for Space Studies in New York has analysed records of local temperatures across the globe, in each case totting up June, July and August to get an overall temperature for this period. The results show that an increasing area of the planet's surface is experiencing highly anomalous heat extremes each year, relative to the period 1951 to 1980 (see charts).
The melting of the arctic ice cap is having effects in the northern hemisphere - it seems to be skewing the jet stream among other things. Climate scientists have been actually too conservative in their estimates of the effects of global warming because natural phenomena are kicking in that their models hadn't incorporated. They're catching up, but this is trying to keep up with a moving target. There's plenty of articles in New Scientist and elsewhere that tie in with the changes in the weather and the increasing number of extreme events.
From June 2 is an article spelling out how Humans and Nature turn American West into a tinderbox.
Worst and wildest: Five off-the-charts weather events shows the kind of extreme weather events that are going to become more frequent. It's a slide show from the last few years, a trip down recent memory lane.
Some things you really can pin on climate change – the heatwave that struck Texas last year, for instance. A long-term rise in temperatures due to greenhouse gas emissions made the hot weather 20 times more likely, modelling suggests.And this article back from 2011 notes that few states seem to be doing any kind of planning to deal with this. They're not factoring in climate change...yet.
The same study found that four other extreme weather events last year can be linked to climate change.
But, while humans may still be in denial, nature appears to be responding in classic fashion. Adapt or die. Climate change drives salmon evolution cites a study finding that salmon are undergoing selection pressure to adapt to changing climate. (Of course, climate change deniers are right there in bed with evolution deniers too.)
Another study offers up the hypothesis that climate patterns over the long term may not be as stable as had been thought, though it's a bit early to regard the findings as conclusive.
The finding does not change our understanding of the warming power of carbon dioxide. In fact, it shows that human CO2 emissions have interrupted a long cooling period that would ultimately have delivered the next ice age.I can only imagine what climate change skeptics will make of that - it won't be pretty. They'll probably argue that this shows global warming is a good thing.
UPDATE: An editorial at New Scientist Earth's past warmth is no get-out clause addresses this today.
CLIMATE scientists have long held that the past 2000 years were almost uniformly cool. Now it seems they were wrong. The 1st century AD looks to have been as warm as today, and the world gradually cooled from then on, right up until the industrial era (see "Tree rings suggest Roman world was warmer than thought").emphasis added Read the whole thing for more.
Climate change denialists, who have never accepted that we are in unusually warm times, will say "told you so". They may also claim that scientists are trying to have it both ways - whatever past temperatures were, they are still evidence of global warming today.
Yet once again, they would be misrepresenting the evidence. The new finding confirms the primacy of human-made carbon dioxide emissions in the warming of the past century. A long-term downward trend in temperature makes it even less likely that recent warming could be due to normal variability.
I'd put together a short diary over the weekend noting that climate change is only going to make the stress on our decaying infrastructure worse. NPR reports there are still people without electricity after the storms that swept through the east. Some related stories on NPR: a discussion that climate change is to blame for the weather - at least in part.
There's three related NPR stories on the Colorado River, here, here, and here, which together show how competing human interests for a limited resource translate into limited options and bad choices - which will only get worse if droughts continue. Dealing with climate change on a global basis is not going to be any easier. (Water wars instead of oil wars?) A book review on NPR from last year looks at Mark Hertsgaard's book Hot - Living Through The Next Fifty Years On Earth - there's an excerpt at the link. Even if we acted today to reduce human contributions to global warming, we already have decades of rising temps to look forward to from what's already happened.
Interesting times ahead. The same people who insist we need to slash government now to reduce the deficit for the sake of our children and grand children see no reason to worry about climate change for those same children. But then, the deficit is nothing but an excuse for what they want to do; climate change is real, is happening now, and is going to keep on happening whether they acknowledge it or not.
There's this funny thing about the future and planning for it. It's easy to put it off, delay taking hard actions in the hopes that something better will come along. But, the dirty little secret of planning for the future is that TODAY used to BE the FUTURE once upon a time. When you're at the bottom of a deep hole, one of those painful questions is why didn't we stop digging sooner? Assuming we have any grand children, how are we going to answer that question?
UPDATE: Thanks for the boost to Community Spotlight. A related diary by Lefty Coaster on the Rec List is worth looking at in connection with this topic: NOAA scientists are linking extreme weather to man-made climate effects. Looks like a consensus is being reached.