Arctic warming full ahead

It may be plunging towards the depths of its long, dark, cold, winter now, but 2010 has been another hot year for the Arctic. Air temperatures over Greenland reached the highest directly recorded levels, according to the 2010 Arctic Report Card. This meant that ice melted from the island’s huge inland sheet for 1 month longer than the average melt period over the past 30 years.

This summary, compiled by the US National Oceanic and Atmospheric Administration (NOAA), also documents an “exceptional” loss of glaciers around Greenland in 2010. 110 square miles of ice, four times the area of Manhattan Island, entered the ocean in the single largest glacier loss at Petermann glacier. “There is now no doubt that Greenland ice losses have accelerated,” the report underlines. “The implication is that sea level rise projections will again need to be revised upward.”

“Cherry picking” is a rotten accusation

Max Planck Institute for Developmental Biology's George Wang

Do you trust the measurements your bathroom scales provide? If not, you share a classic dilemma faced by scientists, which is whether or not their data gives an accurate picture of what they are trying to study. This is an especially sore point in the debate between climate scientists and their critics who differ, for example, over whether it’s OK to exclude temperature measurements from certain weather stations. One accusation is that scientists are just choosing the figures that support their arguments, a practice referred to as “cherry picking”.

Such disputes made me especially interested to see that Max Planck Institute for Developmental Biology scientist George Wang and his colleagues had specifically chosen a set of temperature measurements for their research. Together with Michael Dillon at the University of Wyoming and Raymond Huey at the University of Washington, Wang looked at how temperatures since 1960 would have affected metabolism of ectotherms – better known as “cold-blooded creatures”. They surprisingly found that, despite temperatures changing more slowly where they live, tropical species would be worse affected than those living in cold areas. Could choice of weather stations have influenced this research improperly? Not according to Wang.

“Scientists will exclude data for many reasons, but fundamentally we do it because blindly leaving data in an analysis can bias results,” he told Simple Climate. “In general, scientists in every field have to use judgement based on experience to detect and remove outliers. It is something scientists take very seriously, and it is an integral part of analysing data.”

Climate-driven species creep hangs in the balance

Studies of moss campions in North America have demonstrated that climate change may create tipping points in populations. Credit: Daniel Doak

There is overwhelming evidence that many species have shifted the geographical ranges they live in over recent decades, with some actually becoming more widespread. However, adverse effects of climate change could still await these species, say University of Wyoming’s Daniel Doak and William Morris at Duke University in Durham, North Carolina.

Their research shows competing influences are holding the southern range limit of two Arctic and alpine plants in place, while warming forces the northern limit further north. However, their temperature-driven spread may ultimately prove short-lived, Doak warns. “Up to a point we may see little effect of warming for many organisms,” he says. “But past a climatic tipping point, the balance of opposing effects of warming will likely cease, leading to subsequent rapid declines in populations.”

Rapid climate change poses ecological questions

A male Liolaemus tenuis, an egg-laying lizard species broadly distributed in Central-Southern Chile. Many lizards are ectothermic, or cold-blooded, and those that live in the tropics have had their metabolic rates affected more by increased global temperatures since 1960 than those in colder regions. Credit: P. Victoriano

Although climate changes have happened throughout the Earth’s history, and species have either evolved to cope or perished, the rate of the current changes could now pose a particular problem. So says George Wang, a researcher at the Max Planck Institute for Developmental Biology in Tübingen, Germany, who has been studying global warming’s effects on ectotherms, better known as “cold-blooded creatures”.

“The most worrying aspect of recent climate change is its speed,” Wang told Simple Climate. “Climate changes in the past have generally been much slower than what we see in the last 50 years, so it’s unknown how natural populations will cope. For my field – physiological ecology – the most striking impact of climate change has been to expose just how little we know about how short to mid-term temperature variability will effect populations.”

CO2 dominates Earth’s climate, NASA reveals

A new atmosphere-ocean climate modeling study shows that atmospheric carbon dioxide acts as a thermostat in regulating the temperature of Earth. Credit: NASA GISS/ Lilly Del Valle

Almost 200 years after the greenhouse effect was discovered, and 150 years after its experimental proof, NASA scientists have finally demonstrated that CO2 is the most important greenhouse gas. That’s despite the fact that it only accounts for around one-fifth of the Earth’s greenhouse effect, whereas water vapour accounts for about half, and clouds – water in its solid or liquid forms – contribute a quarter.

“It often is stated that water vapour is the chief greenhouse gas (GHG) in the atmosphere,” write NASA’s Andrew Lacis, Gavin Schmidt, David Rind and Reto Ruedy in top journal Science on Thursday. “This would imply that changes in atmospheric CO2 are not important influences on the natural greenhouse capacity of Earth, and that the continuing increase in CO2 due to human activity is therefore not relevant to climate change. This misunderstanding is resolved through simple examination of the terrestrial greenhouse.”

Seeds of doubt flourish as climate debate hots up

George Mason University's Edward Maibach

Edward Maibach, director of George Mason University’s Center for Climate Change Communication, thinks that much of the US has the wrong idea on climate change. While a large majority think that global warming is happening, he points out that they are too uncertain about the underlying evidence.

“The majority of the American public, our TV weathercasters, and our TV news directors have all reached an erroneous conclusion suggested by industries with a vested interest in the status quo,” Maibach told Simple Climate. “Namely, the majority believe that there is considerable disagreement among scientists about whether or not global warming is happening. A number of studies have shown that over 95 percent of the leading experts on climate science – active climate science researchers – have concluded that global warming – an increase in the global mean temperature relative to a pre-industrial era baseline – is real and that it is largely human-caused.”

Maibach’s “4C” centre published its third survey of US public opinion on climate change in June and July, conducted jointly with Yale University  to get over 1000 people’s outlook. It found that twelve out of every twenty people surveyed think that global warming is happening, compared to just four out of twenty that don’t. By contrast only seven out of twenty thought scientists agreed that it is happening, while nine out of twenty thought that there was a lot of disagreement.

Global warming gives tropical lizards energy problem

Even though global warming is not increasing temperatures in the tropics as much as in the northern temperate zone and the Arctic, the metabolic effects on cold-blooded creatures that live there, such as this caiman lizard, will be greater than on creatures living farther north. Credit: Tim Vickers/Wikimedia Commons

Research published this week suggests that studies of climate change’s impact on the natural world should move from the likes of the polar bear in the Arctic to lizards in the tropics. That’s despite the Arctic seeing a 1.6ºC average temperature rise since 1960, while in the tropics temperatures rose just 0.4ºC over the same time period. “Just because the temperature change in the tropics is small doesn’t mean the biological impacts will be small,” said Raymond Huey, a University of Washington biology professor. “All of the studies we’re doing suggest the opposite is true.”

Together with University of Wyoming’s Michael Dillon and George Wang of the Max Planck Institute for Developmental Biology in Tübingen, Germany, Huey looked at how temperature changes might impact ectotherms, often called cold-blooded species. While lizards are probably the best known ectotherms, the group covers a wide range of organisms, including plants and tiny, single-celled, creatures. Ectotherms can also be found in some pretty cold places – not just the desert.

Naturalists show climate effects from beyond the grave

University of East Anglia's Tony Davy. Credit: University of East Anglia

Ecologist Tony Davy has been inspired by the prospect of working with the new information that insect and flower collectors who have long since passed away are providing him. The British researcher has not invented a time machine to recruit their help, or created an army of zombie assistants. Instead, he has shown that museum collections can be used to obtain data about how species have responded in the past to the temperatures they experienced. That data can help us better understand how our environment will be affected by climate change. “It is exciting to be able to use material collected over hundreds of years for an important purpose that collectors could not have imagined at the time,” Davy said.

To test the idea, the University of East Anglia scientist teamed up with compatriots from the University of Sussex, and the UK’s Royal Botanic Gardens in Kew. “It was really a hunch, but we thought there was a good chance that it could work,” Davy told Simple Climate. Together the team compared when early spider orchids preserved in collections called herbaria were in flower against temperature records for those dates. The results showed that the early spider orchids flowered 6 days earlier for every 1ºC rise in average spring temperature. This matched what team member Michael Hutchings had found when he published 30 years of directly measured data on the relationship between early spider orchid flowering and temperature.

I don’t care what the weatherman says, when the weatherman puts politics ahead of science

Temperatures have risen in the debate between the different US political parties over climate change in recent years - and now the country's weathercasters appear to be more influenced by that than their professional qualifications in their opinions of global warming. Credit: Weather Central

Many US TV weathercasters responded to last November’s “Climategate” scandal more on the basis of political beliefs than meteorology, scientists have claimed. That’s important, Edward Maibach of George Mason University in Fairfax, Virginia, notes, because of their comparatively high profile and large audiences. “TV meteorologists are potentially an important source of informal climate change education in that most American adults watch local TV news and consider TV weather reporters a trusted source of global warming information,” Maibach and colleagues write. “At least temporarily, Climategate has likely impeded efforts to encourage some weathercasters to embrace the role of climate change educator.”

“Climategate” refers to the publication of hacked emails from the Climatic Research Unit (CRU) in East Anglia – which is jointly responsible for one of just three global temperature records. Among these were statements that suggested climate researchers may have inappropriately tampered with and illegally avoided sharing data, and tried to suppress other scientists’ work. Since then a series of enquiries found that the conclusions of their research are not in doubt, although they did fail to display the proper degree of openness.