But, how do we know this is right?

While many reporters cover climate issues - like this one taking notes during a demonstration for the enforcement of Kyoto Protocol - some of them only confuse the issue. Credit: ItzaFineDay

Be careful – the people you trust may be leading you astray. Are they worthy of your faith in them? Does what they say really represent reality?

These may sound like strange ramblings, but if we all answered truthfully we might better understand the major causes of the current debate on climate change. Everyone in the world depends on their own set of sources of information. We share many of them, like television programs and newspapers, with others. We also have some sources that others don’t, like our friends, or maybe an obscure little website. But, as Australian psychologist Ben Newell and climate change researcher Andrew Pitman warned earlier this month, we often don’t realise when these sources are biased.

Spider orchid flowering crawls forward with warming

An early spider orchid

Despite global warming accelerating since the 1970s, when early spider orchids in the UK flower still varies with temperature in exactly the same way that it has for the past 150 years. By studying preserved plant specimens known as herbaria, researchers from the Universities of East Anglia, Sussex and Kent have found that orchids consistently flower 6 days earlier for every 1ºC rise in average spring temperature. Measurements of how species react to climate changes are rare, and so this first clear demonstration that herbaria can fill these gaps creates a powerful new scientific weapon.

“It is estimated that some 2.5 billion specimens of flora and fauna are held in biological collections worldwide,” the University of East Anglia (UEA)’s Anthony Davy and colleagues wrote in the Journal of Ecology this week. “With appropriate validation, the exploitation of this resource will have increasing relevance and value as we seek to understand and predict the consequences of continuing climate change.”

Immense energy emissions challenge “not understood”

Carnegie Insititution of Washington's Steven Davis

Sometimes, climate change seems unstoppable – so much so, it’s tempting to ask: ‘Why bother doing anything about it then?’ Steven Davis of the Carnegie Institution of Washington and his colleagues have provided one answer. They have found that while the power generation facilities and transportation we currently use guarantee some CO2 emissions, those emissions will not themselves reach levels that could cause dangerous climate change.

“The result is hopeful in that what we’ve already built won’t put us over the 2ºC benchmark,” Davis said. A 2°C temperature rise from pre-industrial averages is a stated aim of the Copenhagen Accord, agreed by the world’s countries in December last year. However, Davis warns that taking the right steps to stop emitters yet to be built taking global temperature rises through this limit is a difficult, in fact almost impossible, challenge. “The necessary transition in our energy system is incredibly daunting,” he explains. “The immensity of the challenge is not commonly understood, the political will is lacking, and there are few alternative energy technologies that can attain the required scale.”

Saturday round-up: All quiet on the northern seas

The Arctic may become more serene, as a slowly warming sea stabilises atmospheric circulation, reducing the frequency of "polar lows", with the progress of climate change. Image © Science/AAAS

Highly-waterproofed sailors used to fighting howling winds and avoiding icebergs in the world’s northernmost oceans are set to have their struggles eased by climate change. That’s because, not only is Arctic ice area decreasing, but severe North Atlantic storms will decrease in frequency as the world warms.

These storms are small and therefore difficult to observe, Matthias Zahn and Hans von Storch from Germany’s GKSS Research Centre write in top journal Nature this week, but still dangerous. “Accompanied by strong winds and heavy precipitation, these often explosively developing cyclones – termed polar lows – constitute a threat to offshore activities such as shipping or oil and gas exploitation,” they say.

Polar lows, or ‘Arctic hurricanes’, start as low level airflows that are built up by air circulation caused by large temperature differences between different levels of the atmosphere. They occur every winter, and while there are weaknesses in direct historical measurement, a previous simulation based on climate data from 1948–2006 showed an average of 56 polar lows per year.

Has climate change cut plankton’s oxygen production?

A number of marine diatom cells from the Pleurosigma family, which are an important group of phytoplankton in the oceans. Credit: Michael Stringer, photo courtesy of Nikon Small World.

Simple Climate readers are alongside some of the world’s finest minds in asking questions that trouble even leading climate scientists. That’s the conclusion that I’ve reached after trying to help reader Marc Piore answer a question based on research covered here back in July.

The particular study that troubled him was an assessment of ocean phytoplankton levels from 1899 to today published in top journal Nature. In it, Boris Worm and his colleagues at Dalhousie University, Canada, found that the populations of phytoplankton in the oceans had fallen 40% since 1950, crediting climate change as the cause of the decline. At the time Worm was widely quoted as saying that phytoplankton is responsible for producing “half the oxygen we breathe”.

Faulty power brakes to prevent emergency CO2 stop

This graph shows the projected decline of carbon dioxide emissions in gigatons (billions of tons) from existing energy and transportation infrastructure (red wedge) over the next 50 years, compared to three emissions scenarios (dotted lines) from the Special Report on Emissions Scenarios (SRES) Intergovernmental Panel on Climate Change (IPCC). High, middle, and low emissions projections correspond to the SRES A1G-FI, A2, and B1 scenarios, respectively. Image courtesy of Stephen J. Davis

A dead stop on building CO2 emitting devices would be enough to avoid dangerous climate change, scientists have claimed in top journal Science this week. However, the world is so committed to using fossil fuels to provide energy, the Carnegie Institution’s Steven Davis says it will be difficult to avoid directly replacing existing emitters. “CO2 emitting infrastructure will expand unless extraordinary efforts are undertaken to develop alternatives,” Davis and his colleagues write.

Energy generation and transportation will emit around 496 billion tonnes of CO2 over the next 50 years, Davis, his Carnegie colleague Ken Caldeira, and Damon Matthews of Concordia University in Montreal calculated. That would increase atmospheric CO2 concentrations from 385 parts per million (ppm), which itself is a big rise from around 280 ppm in pre-industrial times, but the increase would stop at around 430 ppm. This is below the 450 ppm level that’s widely accepted will cause a dangerous 2°C temperature increase from pre-industrial averages. Davis and colleagues predict the average global temperature rise in this scenario would be about 1.3°C. “The answer surprised us,” said Davis. “Going into this study, we thought that existing sources of CO2 emissions would be enough to push us beyond 450 ppm and 2°C warming.”

Geo-engineering “quick fix” is a big risk

Beijing Normal University's John Moore, who is also affiliated with the University of Lapland and the University of Oulu in Finland. Credit: Beijing Normal University

Climate change is leaving the world’s northernmost inhabitants literally lost for words, according to Beijing Normal University‘s John Moore. “Arctic indigenous people have no local names for bird species migrating into their areas, showing that they have not been seen over the history of their oral tradition,” he explains. Moore also has his own personal connection to the impact of global warming, with ice shelves in Antarctica where he worked in the 1980s having ceased to exist since. Moore expects that further breakup and retreat of ice will follow as temperatures rise. “Dramatic changes are very clearly seen in glaciers in many mountain regions, Greenland’s melting and glacier flow, and the on-going acceleration of glaciers in parts of West Antarctica,” he says.

While these likely impacts are clear, other future happenings are not. “We have been doing a CO2 experiment for centuries and we are still not sure of all the detailed impacts,” Moore says. We know less still about a group of suggested methods for tackling climate change without reducing greenhouse gas emissions, together known as geo-engineering, making using them a potentially high-risk strategy, Moore notes. “Modifying the climate is bound to be risky since every living thing depends on it,” he says. “Human civilization is about as old as the stable climate period of the Holocene,” Moore says. “We know that over the previous 100,000 years climate was very unstable compared with this period. It seems civilization’s origins relied on a stable climate – cities dependent on agriculture would have been unsustainable in a variable climate.” However, geo-engineering could help keep the climate stable while we reduce our greenhouse gas emissions, he adds. “There may be real benefits in helping to get us over the fossil fuel dependency and on to a more sustainable track.”

Saturday round-up: Climate change threatens to quell China’s green revolution

A farmer in Guizhou province, China, holds his poor harvest. Severe drought has greatly affected crops in many parts of China this year. Credit: Xinhua

China’s remarkable recent surge in agricultural output is at risk from climate change. However,  how much risk won’t be clear without better regional climate predictions and understanding of how crops will react to their altered environment. That’s according to Peking University’s Shilong Piao and his colleagues. “Climate simulations point to serious potential vulnerabilities in China’s future agricultural security,” they wrote in top journal Nature on Thursday, “but extensive uncertainties prevent a definitive conclusion.”

In part those uncertainties come from Chinese farming’s success over the past four decades, increasing rice, maize and wheat yields by 90, 150 and 240 percent respectively. These improvements are vital as the country has just 7 percent of the world’s arable farmland available to feed 22 percent of the world’s population. However, they also obscure the impact of more frequent heat-waves, retreating glaciers and an average 1.2ºC temperature rise in China since 1960. “The improvements of crop management have been so important that they prevent a clear conclusion on the net impact of historical climate change on agriculture,” the team writes.

Stemming the invisible energy flow

Columbia University's Shahzeen Attari

Shahzeen Attari says that we need to change both our behaviour and adopt energy-efficient technologies to land the biggest individual blows in the fight against global warming. While this may sound like just another call to try harder to cut greenhouse gas emissions, it’s instead an attempt to tackle the downsides of each approach. As a researcher working at New York’s Columbia University she has found that most people’s first choice to try and cut emissions is to reduce – or curtail – their energy usage.

“I think people go for curtailment automatically because it does not involve any upfront cost, so it is inexpensive,” Attari said. “It may be thought of as easy to do and think about in the short term. The problem is that it requires continued vigilance to maintain one’s curtailment efforts, so people may relapse into using as much energy as they did before.”