Last February, as the snow just kept piling up in Washington, D.C., Sen. Jim Inhofe, R-Okla., and his family built an igloo down the street from the Capitol and labeled it “Al Gore’s new home.” And the Virginia Republican Party ran TV ads telling viewers to call legislators who supported climate-change legislation “and tell them how much global warming you get this weekend. Maybe they’ll come help you shovel.”
Of course, the “Snowmageddon” jokesters had no way of knowing at the time that within less than five months the snowshoe would be on the other foot. By early July, with much of North America broiling in record-shattering heat, most climate-change holdouts were keeping a low profile. (But not Inhofe, who defiantly lectured a sweating ABC News team, “We’re in a cycle now that all the scientists agree is going into a cooling period.”)
Meanwhile, some environmental groups pointed to the blistering July temperatures as confirmation that we’ve headed over the cliff of global climate change. The National Wildlife Foundation rushed out a report supplement titled “Extreme Heat in Summer 2010: A Window on the Future” filling it with pictures of sweating city-dwellers and hot-colored charts. The Natural Resources Defense Council put out a press release in which its climate-center director announced, “Welcome to what might be termed ‘the dark side of climate change.'”
Back in the 1990s, the major environmental groups made a decision not to highlight extreme weather events as early signs of global warming. Should they have stuck to that policy? When heatwaves, droughts and floods are exhibited as evidence of climate disruption, does it make it that much easier for people like Inhofe to whip up more confusion the next time a winter storm hits? Is there any cool-headed way to talk about the crazy climate of recent years
The Odds on Odd Weather
Given the complexity of climate science, it’s not surprising that the best way to get the attention of the media and the public is to talk about exceptional weather that’s happening right now rather than the bigger threat of long-term climate disruption. But that makes life difficult for those who study climate for a living.
One such researcher is Katharine Hayhoe, an associate professor at Texas Tech University. She sees a clear necessity to come back hard against fatuous arguments that, she says, go something like, “Well, you know, temperatures are cooling in the month of September in Erie, Pennsylvania, so how can the planet be warming?” But, she warns, climate scientists have to be careful themselves not to go beyond the data: “It is very tempting to seize on a single dramatic event, but we have to stay true to what we know, to stick to terms like ‘consistent with’ and ‘risk of.'”
In public statements, most climate scientists are indeed careful to stress that we cannot draw conclusions from individual extreme weather events. But Michael Mann, director of the Earth System Science Center at Penn State University, is now thinking such caution may have gone too far.
He says many of his colleagues, weary of being attacked by people like Inhofe, tend to “jump too soon,” starting their responses to reporters by discounting the relevance of individual weather events. But by understating the links, he believes, they are “erring in the opposite direction,” which in itself can be misleading. “Statistics show very much that these events really are part of bigger trends,” he stresses.
To illustrate, Mann uses a metaphor popular among climate researchers these days: “Suppose you’re betting on dice, but that someone had replaced the five on this particular die with a second six. If you don’t know this, you might get cheated out of a lot of money. But when you demand your money back, can you point to any one roll of that die that you can prove lost you money? No, you can’t.” But, he says, it’s a fact that the size of your losses is a direct result of the change in the die.
Similarly with the Earth’s atmosphere, he says, statistics tell us that shifts in climate have contributed to extreme weather: “As the numbers start piling up, you can say that the numbers have been shifted by climate change. A 1,000-year event becomes a 30-year event.”
To follow year-to-year climatic trends through the centuries before weather data were being recorded, scientists like Mann can use indicators like tree rings. But it is usually impossible, he says, to detect trends in shorter-term climatic extremes that occurred in the distant past.
On the other hand, daily weather data that have been recorded for 50, 100, or more years in many places can tell us a lot about extremes. And, says Mann, “When extreme events that actually occurred are the ones you’d expect based on climate-change models, you have a lot more confidence.”
“If we were seeing a lot of longer, more intense cold periods, we’d all be scratching our heads. But when you confirm what the hypothesis proposed, you have an increased degree of confidence.”
And confidence is increasing. Last year, 15 climate scientists published a paper in the Proceedings of the National Academy of Sciences that contained this straightforward statement, based on the most recent Assessment Report by the Intergovernmental Panel on Climate Change (IPCC): “It is now more likely than not that human activity has contributed to observed increases in heat waves, intense precipitation events, and the intensity of tropical cyclones.”
Furthermore, even on a warming planet, regions with traditionally cold winters will still have plenty of below-freezing weather; when that cold air combines with moist air masses (in a generally warmer atmosphere that’s able to carry more water vapor than it used to), a lot of moisture can suddenly get dumped in the form of snow.
Hayhoe helped write a June 2009 report published by the U.S. Global Change Research Program finding that the share of precipitation falling as snow rather than rain is increasing in the northeastern United States. Furthermore, said the report, “Heavy snowfall and snowstorm frequency have increased in many northern parts of the United States.” Six months later, with the northern and middle Atlantic coast paralyzed by record snowfall, Hayhoe and her co-authors could be even more confident that the trend they had observed was not a mirage.
But if climate models project with some assurance that present and future emissions of greenhouse gases will lead to rapid warming of the atmosphere and extreme weather, is it even necessary to continue digging into past climate and weather records for evidence of change? Do historical studies add any useful information as we plan for the future?
Sixteen scientists who contributed to a 2008 report for the U.S. Climate Change Science Program stressed that while the past does not hold all the answers, it is important to learn what it can tell us. The first step, they explain, is “detection” – establishing that changes have occurred in some type of extreme, say heat waves, over time. Then comes the second step, “attribution”:
Attribution further links those changes with variations in climate forcings, such as changes in greenhouse gases, solar radiation, or volcanic eruptions.. . Attribution often uses quantitative comparison between climate-model simulations and observations, comparing expected changes due to physical understanding integrated in the models with those that have been observed.
Such a comparison can be seen in graphs plotted by University of Oklahoma researchers. In them, an index including several kinds of extreme climate events can be seen increasing over recent decades in a way that can’t be explained by natural variation. But when greenhouse emissions are included in climate models, observation and theory align very well.
When Extreme Heat
Becomes Routine
If last summer’s brain-cooking heat seemed to be unusually persistent, it wasn’t just your fevered imagination. Weather records show that occurrences of two-day and three-or-more-day-long runs of exceptionally high temperatures have been increasing steadily since 1960. The trend toward more extra-hot days, and especially extra-warm nights, has been strongest, as we’d expect, in urban areas where concrete and asphalt trap heat and vegetation is sparse. But rural areas and suburbs have also seen increases.
A half-century ago, record high and record low temperatures occurred at approximately the same rate in the United States. Now record highs are happening at least twice as often as record lows, and the ratio might be as high as four-to-one.
One link between heat waves and human-induced warming of the atmosphere is simply a matter of statistics. Daily temperatures are distributed like most phenomena, in a bell-shaped curve, with most readings heaped up in the middle, near the average for the date, and the rarer extremes tapering away in both directions as “tails.” As the earth warms, that curve tends to shift to the right, toward higher temperatures, with its right tail leading the way.
Even if the bell curve stays exactly the same shape as it moves, a small shift can lead to many more heat waves. Notes Michael Mann, “The one-degree Celsius increase we have seen in average temperature, for example, appears to be leading to a doubling of the rate at which record-breaking temperatures occur.” That happens because as the curve moves right, the “fatter” part of the tail moves into “extreme” territory.
Extreme Rains,
Extraordinary Snow
In recent years, precipitation patterns appear to have gone haywire, not just in Pakistan but on every continent. Katharine Hayhoe has seen this up close: “In the five years I’ve lived in West Texas, we’ve had a 111-day rainless stretch – the longest ever recorded – and two ‘100 year’ rainfalls” – ones so heavy that such an event occurs only once per century on average.
“But,” she says, “it all makes sense from a basic physics perspective. The atmosphere is holding more water vapor. Storm systems, when they come, have more to work with.”
Warmer air is capable of holding more water vapor than is cooler air. As a consequence, the concentration of moisture in the atmosphere also has been increasing since the ’60s, both in the United States and across the globe. A comprehensive 2007 study led by Katharine Willett, now at Yale University, concluded that the increases in humidity observed planet-wide can be attributed to human influence and that natural forces alone cannot explain the change.
With more moisture in the air, an increasing proportion of precipitation is coming in the form of more intense rainstorms around the world. Over the past 30 years, the southeastern United States has seen simultaneous increases in droughts, wet years, and strong rainstorms. These big swings in precipitation are related to the continuing rise in Atlantic Ocean surface temperatures and the increasing variability of those temperatures. The ocean temperature increase has been attributed to greenhouse emissions; the degree to which emissions affect variability in surface temperatures is less well understood.
Numbers of years with extremely high snowfall have declined since the 1950s over much of the country. That was to be expected, because with climate change, weather cold enough for snow is now even more rare in warm regions like the Southeast.
However, extremes follow a different pattern from totals. There has been a slight upward trend in strong snowstorms over the past century in the United States. What part of that trend you see depends on where you live. Warmer areas of the country are seeing fewer big snowstorms, but the upper Midwest and the Northeast are getting hit with more of them.
No News Is Bad News
Whatever happens on the ground, in the sea and in the atmosphere in coming decades, it is very likely that public discussion of the climate will tend to focus on events like heat waves, floods and storms more than on the invisible, and ultimately more important, transformation of the planet-wide climate.
In a 2007 essay, Andrew Revkin of the New York Times explained why storms make headlines but climatic disruption does “not constitute news as we know it”:
… the incremental nature of climate research and its uncertain scenarios will continue to make the issue of global warming incompatible with the news process. Indeed, global warming remains the antithesis of what is traditionally defined as news…Journalism craves the concrete, the known, the here and now and is repelled by conditionality, distance, and the future.
But could it be that the kind of energetic public discussion we saw following last winter’s Snowmageddon can actually help remedy the situation, by introducing more people to the complex forces that are taking our climate on this wild ride? Do more people now know, for example, that if there is extraordinary weather again this winter, it can be entirely consistent with what we’d expect when living in a warmer, moister atmosphere? Will more of us see in next summer’s heatwaves the roll of loaded dice?
When I asked Michael Mann those questions, he chuckled. “Well, yes, I hope the past year has provided a learning opportunity” for Americans.
But will we actually learn from it? On that question, Mann – who makes his living estimating statistical confidence – did not seem very confident at all.
This article appears in Dec 23-29, 2010.
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“Warmer air is capable of holding more water vapor than is cooler air. As a consequence, the concentration of moisture in the atmosphere also has been increasing since the ’60s, both in the United States and across the globe. A comprehensive 2007 study led by Katharine Willett, now at Yale University, concluded that the increases in humidity observed planet-wide can be attributed to human influence and that natural forces alone cannot explain the change.”
And there it is. Not only are hot summers caused by global warming, but somehow so too are cold winters. Just needed some smart scientists to explain how. Quite possibly this is the most absurd claim in the history of the global warming agenda, though by no means unexpected. I have been wondering why it took this long since people are having a difficult time with “climate disruption” for a couple of reasons. First, the whole concept is far from scientific certainty. Second, given the rough economy, nobody gives a crap about a cause which environmentalists cannot successfully demonstrate will affect anybody in a material manner. People do see very dire economic ramifications to all of the proposed solutions.
So by all means climate “scientists”, keep pushing your science in the self interest agenda. Cause enough alarm with your findings and that next research grant is nearly a sure thing. The rest of us will continue with our lives unaffected by ozone holes, spotted owls, or global climate disruption.
Climate scientist are after the fact science experts, they always say yea see this is what we were predicting, one fact for you scientist, America never going to sign on to this UN climate change BS, where the world has their hand out and they want us to kill out economy , UN can go to hell, Obama will soon be elected out,
This is VERY good. More, please.
Setting aside the twenty years I’ve studied climate science, in the half century and more since I was held up to view the seven peaks from the third floor of hospital hill I have seen the change and can only conclude that there are none so blind as those who refuse to see.
Sirs:
I agree with Thomas Ware, this article is important and well-written.
For the classic fossils among TSW’s readership, I would encourage you to become more familiar with reality. The re-insurer, Munich RE, recently published a very inconvenient truth for the case of the climate change deniers. The insurance industry has seen the number of insurance claims and the cost of those claims (inflation adjusted) paid out due to extraordinary and destructive weather events rise by 300% between 1980 and 2009 on an annual basis. This is a fact that climate deniers will simply disregard since it inconvenient to their inverted cranial-rectalitis world view.
Another fact that will be extremely inconvenient for the average climate change denier is the recent study in northern India where it was discovered that a one degree Celsius rise in average temperatures has been found in certain districts to correspond to a 10% decrease in rice crop harvests. So much for the “carbon dioxide is plant food” folly, I’d suggest.
Abnormally warm conditions in Russia’s grain belt last summer resulted in a 30% decline in harvests, a grain export embargo in Russia and a 100% rise in world wheat prices in the past 7 months. Did you notice that 59 cent per pound turkeys were unavailable this year in the supermarkets? Well, climate disruption does have its consequences.
So, go ahead Americans, deny climate change all you want. Avoid facts, avoid grocery shopping, avoid Texas in the summer heat. But by all means realize that reality will inevitably always bite you where you’ve buried your head.
Many climate change denialists and believers make the same exact mistake, and point to one season or one year, or one single piece of data, as evidence to support or contradict the warming of our planet. No SINGLE season or storm is indicative of either, and no single observation does either. Climate warming science is about long-term trends and the correlation to our lifestyle and effect on the environment. There is no UN or communist or Obama conspiracy. And simply being against science because it is somehow anti-religion is hypocritical. Science is a methodology…the same reason we have medicine that saves lives, cars, computers, airplanes, and all sorts of things we take for granted and don’t dispute…all come from science and the scientific method. If you would rather believe in conspiracies rather than acknowledge we have some responsibility to take care of our planet for future generations….than believe your horseless carriage runs on magic, the earth is flat, the moon is made of cheese. Sure, there is merit to the idea that some climate change does occur naturally…but we are accelerating it immensely by our lifestyle and lack of willingness to change our habits. It’s much easier to complain, attack, and believe in clowns like Sen. Inhofe, than accept any responsibility on how we live our lives, or to change the lifestyle that is fed and sold to us on TV…drive big cars,shop at walmart, throw stuff away when it breaks, buy homes we can’t afford…that’s the American way…why bother change? making small changes to our daily lives is too much trouble, right? even when it can save money by reducing your household energy bills or what you pay at the gas station? or created jobs in “green” industries? it’ll only be our children that will pay the price? who cares, right? All scientists and environmentalists are asking is for people to TRY, why is that so hard to do?
To quote Mark Twain: “There are three kinds of lies: lies, damned lies and statistics.”
This article demonstrates the principle rather well. The print version of the article highlights this statement
: “A half-century ago, record high and record low temperatures occurred at approximately the same rate in the United States. Now record highs are happening at least twice as often as record lows, and the ratio might be as high as four-to-one”.
It is convenient to pick the 50 year time frame, because that cuts out the 1930's, a period in which far more high and low temperature records were set. For the summer months of June, July, and August, 52 statewide record highs were set in the 1930's, compared to 11 in the 1990's and 4 in the 2000's. The ratio of current high to low records is a poor measure, given the small data set.
It is interesting the Michael Mann is quoted so widely, and referred to as a person “who makes his living estimating statistical confidence” An investigation into some of Mann's work was led by statistician Edward Wegman of George Mason University. Wegman said Mann made a mistake in the way he centered the data. He suggested that Mann and his colleagues were brash young researchers who should have gotten more help on their math.
“These guys are going off with very little background,” he said. “They’re self-taught in the world of statistics.”
With regard the remark in the comments section by Raymond Duray on the costs of storm related insurance costs, the report he cites also states that losses from severe weather have gone up due to socio-economic conditions, not from changes in frequency or severity of weather events.
While I agree that there are environmental gains to be made in attempts to cut emissions, I think we can get more environmental “bang for our buck” by not focusing on CO2. Articles such as this one perpetrate the impression that global warming is far more serious a concern than the actual data, properly analyzed, demonstrates.
“All scientists and environmentalists are asking is for people to TRY, why is that so hard to do?”
No. All scientists are asking for is more money for reaearch grants, which won’t be given if you don’t sufficiently alarm the public with admittedly doctored data and hockey stick charts scaled to make statistical noise look like dire temperature change.
Why worry about the future when you are alive today? So what if global warming is real, it won’t affect my life as the real bad results won’t happen for say a hundred years or so. Who cares if what we do today leaves a fouled up world for the next generation or maybe the one after that, we have what we want today.
In reality I feel that we are affecting the world, climate and resources. How many people and how much machinery can we keep producing, some where there is a limit. I have a real difficult time wondering how people that have children can just go on in the same fashion of living, leaving a real mess for their offspring, this generation and down the line.
Global warming is just one small part of a major issue, and we treat them all the same, stick our heads in the sand and claim that our world is good so why worry about the future.
The human race in a 1000 years? I don’t think we will still be around in 200 years(what would the world population be then, if we survived, 10-15 billion?) at the rate we are going now.
In case anybody missed it, in the last couple of weeks we have seen more global warming fallout.
The east coast is getting hammered with yet another brutal cold and storm event. In Florida, manatees are dying from cold stress, this makes the second winter in a row for that. If the earth warms much more they could all die from the cold. I even heard of a zoo that was giving blankets to the monkeys to help stave off the chill of global warming.
Yet more global warming hitting most of the US. Worst winter in decades.