Saturday round-up: Europe’s CO2 cut costs fall

Connie Hedegaard, European Commissioner for Climate Action, suggests that Europe should cut its CO2 emissions further now the cost of doing so has fallen. Credit: Simon Wedege

Connie Hedegaard, European Commissioner for Climate Action, suggests that Europe should cut its CO2 emissions further now the cost of doing so has fallen. Credit: Simon Wedege

After finding that it will be cheaper than originally thought to reduce greenhouse gas output, the European Commission has invited its member countries to debate deeper emissions cuts. According to Connie Hedegaard, European Commissioner for Climate Action, reducing greenhouse gas emissions to 20% below 1990 levels by 2020 will cost €32 billion less than suggested in 2008. That puts the cost at €48 billion per year or 0.32% of the European Union (EU)’s gross domestic product (GDP), which is one measure of its economic output. Consequently Hedegaard floated the idea of reducing emissions still further, by 30% from 1990 levels by 2020, on Wednesday.

The recession is the main reason for this reduced cost. A week ago the European Comission announced that verified EU emissions of greenhouse gases in the EU Emissions Trading System (ETS) in 2009 fell by 11.6% from 2008. “Due to the crisis the significant drop in emissions does not come as a surprise,” Hedegaard said. Two other reasons include cheaper supplies of natural gas, which produces less CO2 when burnt than coal, and more expensive carbon credits in the ETS, which is designed to reduce greenhouse gas production. Read the rest of this entry »

Not just a drop in the ocean

Quicker cycling of water from the land and sea into the atmosphere and back down as rain has made the world’s rainfall increasingly localised, according to Paul Durack. “Arid regions have become drier, and high rainfall regions wetter, with these changes corresponding to global surface warming” the Australian researcher explains. He finds this especially worrying, given how dry his own country is.

A) Sea surface salinity changes over 1950-2000. Red areas become saltier through enhanced evaporation, and blue fresher through enhanced rainfall. B) The mean annual water transport over the ocean. Blue is where more rainfall than evaporation falls over a year, whereas orange is the opposite - the belt in which Australia is located.

A) Sea surface salinity changes over 1950-2000. Red areas become saltier through enhanced evaporation, and blue fresher through enhanced rainfall. B) The mean annual water transport over the ocean. Blue is where more rainfall than evaporation falls over a year, whereas orange is the opposite - the belt in which Australia is located.

At one level, anyone who’s seen a puddle dry out can understand the fact that increased temperatures might drive more water into the atmosphere. “Evaporation at the ocean surface is linked to atmospheric and ocean surface water temperatures,” Durack underlines. However, a warmer world speeds up the movement of water for a second important reason. “The more temperature increases, the more water the atmosphere can hold,” the Australian Commonwealth Scientific and Research Organization (CSIRO) scientist tells Simple Climate. This higher atmospheric water content accelerates the water cycle. Read the rest of this entry »

Saturday round-up: A wave of evidence

John Lyman (left) holds an expendable bathythermograph or XBT, a device that was dropped from ships to obtain temperature. Gregory Johnson (right) holds an Argo Float, an autonomous, free-floating ocean device that collects a variety of data, including temperature. Credit: NOAA

John Lyman (left) holds an expendable bathythermograph or XBT, a device that was dropped from ships to obtain temperature. Gregory Johnson (right) holds an Argo Float, an autonomous, free-floating ocean device that collects a variety of data, including temperature. Credit: NOAA

The science journals this week are awash with measurements from watery bodies demonstrating the progress of global warming. In particular an international collaboration has analysed sea temperatures around the world, finding a strong recent 15-year warming trend. The resulting increase in energy contained in the oceans is equivalent to the energy spent running 500 100-watt bulbs for every person on the planet. “The ocean is the biggest reservoir for heat in the climate system,” said Josh Willis, an oceanographer at NASA’s Jet Propulsion Laboratory. “As the planet warms, we’re finding that 80 to 90 percent of the increased heat ends up in the ocean.”

Willis teamed up with scientists from the US National Oceanographic and Atmospheric Administration (NOAA), Japan’s Meterological Research Institute, the UK’s Met Office and the University of Hamburg, Germany. They brought together five sets of data separately assembled using equipment known as expendable bathythermographs, or XBTs. Designed primarily to estimate ocean sound speed for submarine warfare, how XBT measurements are interpreted has a large effect on their final results. Read the rest of this entry »

What price global warming?

University of New South Wales' Steven Sherwood.

University of New South Wales' Steven Sherwood.

Steven Sherwood believes that economists are too confident in humanity’s ability to adapt to the effects of global warming. Sherwood is a University of New South Wales, Australia, climate change researcher, and recently published research showing that a 12ºC rise would make most of the planet uninhabitable.

“I noticed that economists and policy experts were, in effect, assuming that we could adapt to any amount of warming, even 12ºC,” he explained. “I suspected that such warmings would be beyond human physical tolerance, and realised nobody had examined this.” Economists produce cost estimates for climate change that are strongly influenced by the probability and cost of the worst possible outcomes. The consequences that they assume for those worst case scenarios are mild compared to what Sherwood says “the laws of physics say will happen”. “That means their calculations are too low,” he added. “It may be that their costs are too low even for more modest warmings.” Read the rest of this entry »

Saturday round-up: Climate change squashes lizards

Biologist Barry Sinervo holds a pregnant mesquite lizard (Sceloporus grammicus), one of the species he is studying in his lab at UC Santa Cruz. Some local populations of mesquite lizards in Mexico have gone extinct due to rising temperatures. Credit Jim MacKenzie/UCSC

Biologist Barry Sinervo holds a pregnant mesquite lizard (Sceloporus grammicus), one of the species he is studying in his lab at UC Santa Cruz. Some local populations of mesquite lizards in Mexico have gone extinct due to rising temperatures. Credit Jim MacKenzie/UCSC

A survey of 48 Mexican spiny lizard species has found that 12% of local populations have gone extinct since 1975, with climate change being blamed. A international collaboration of 26 researchers published the results of its study of 200 locations across Mexico in the journal Science on Friday. “Our findings indicate that lizards have already crossed a threshold for extinctions,” writes the team led by Barry Sinervo of the University of Santa Cruz.

As well as the Mexican survey, the team’s judgement is based on extinctions seen from 1975 to 2009 on four other continents. Combining all these data they estimate that 4% of local populations have gone extinct worldwide since 1975 and project that by 2080 local extinctions will reach 39% worldwide, and species extinctions may reach 20%. Read the rest of this entry »

What can we get out of the ozone hole, 25 years on?

Joe Farman, Brian Gardiner and Jon Shanklin (L-R), the authors of the 1985 paper in which the Antarctic ozone hole was first documented. Here they are pictured with a Dobson ozone spectrophotometer, used to determine stratospheric ozone concentrations. Credit: British Antarctic Survey.

Joe Farman, Brian Gardiner and Jon Shanklin (L-R), the authors of the 1985 paper in which the Antarctic ozone hole was first documented. Here they are pictured with a Dobson ozone spectrophotometer, used to determine stratospheric ozone concentrations. Credit: British Antarctic Survey.

When it comes to the duration of problems in our world’s atmosphere, the greenhouse effect and the ozone hole are the long and the short of it. “The ozone hole went from barely detectable to 50% depletion in around a decade, showing just how fragile our planet is,” explains Jon Shanklin, head of the British Antarctic Survey‘s Meteorology and Ozone Monitoring Unit. “Climate change is expected to proceed more slowly, however we are committing ourselves to changes that will last for many centuries, rather than the single century that should see the ozone layer back to normal.” Read the rest of this entry »

Saturday round-up: Humanity’s upper warming limit

This map shows the maximum wet-bulb temperatures reached in a climate model from a high carbon dioxide emissions future climate scenario with a global-mean temperature 12 degrees Celsius warmer than 2007. The white land areas exceed the wet-bulb limit at which researchers calculated humans would experience a potentially lethal level of heat stress. Credit: Purdue University graphic/Matthew Huber

This map shows the maximum wet-bulb temperatures reached in a climate model from a high carbon dioxide emissions future climate scenario with a global-mean temperature 12 degrees Celsius warmer than 2007. The white land areas exceed the wet-bulb limit at which researchers calculated humans would experience a potentially lethal level of heat stress. Credit: Purdue University graphic/Matthew Huber

Global warming of 12°C would make most areas of the world uninhabitable, and burning all the fossil fuels on the planet could get us to this level. That’s what Steven Sherwood of the University of New South Wales, Australia, and Matthew Huber of Purdue University, USA, claim.

Writing in a paper published online in the Proceedings of the National Academy of Science this week, the scientists examine the heat stress that humans and mammals can bear. This is assessed through a measure known as wet bulb temperature, which combines the effect of heat and humidity. The world’s hottest areas normally have low humidity, referred to as “dry heat”, Huber explained. “When it is dry, we are able to cool our bodies through perspiration and can remain fairly comfortable,” he said.

They say that currently wet bulb temperatures on the planet never exceed 31°C, while humans and other mammals would die if exposed to levels above 35°C for extended periods. They predict that conventional temperature rises of 7°C would begin to see wet bulb temperatures above 35°C in some regions, while 11-12°C rises would force humans out of most areas where they currently live . Read the rest of this entry »

Running the numbers

Continued growth in CO2 emissions could lead to dangerous global temperature rises. The red lines represent a "business as usual" scenario that we might already be following, while the blue lines are what is needed to keep emissions below the dangerous 2°C level. Credit M. Meinshausen

Continued growth in CO2 emissions could lead to dangerous global temperature rises. The red lines represent a “business as usual” scenario that we might already be following, while the blue lines are what is needed to keep emissions below the dangerous 2°C level. Credit M. Meinshausen

In 2008, 2010 humans across the world were responsible for emitting greenhouse gases equivalent to 46 37 billion tonnes per year of CO2. In that year there were 6.7 6.9 billion humans on the planet. On average, each human on the planet was therefore responsible for the equivalent of 6.9 5.3 tonnes of emissions. Joeri Rogelj, who spoke to Simple Climate last week, suggests that by 2020 emissions should not exceed the equivalent of 44 billion tonnes per year of CO2. By that time the UN anticipates the world population reaching 7.6 billion, in its medium-growth level prediction scenario. This would mean a cut in emissions to of 5.8 tonnes per person.

The Kyoto protocol and subsequent negotiations have focussed on 1990 as the base year from which to reduce emissions. Rogelj and his colleagues estimate that in that year greenhouse gases equivalent to 36 billion tonnes of CO2 were emitted. Until shortly before the end of the negotiations for the Copenhagen Accord in December, the draft agreement still contained targets specifying a global reduction of 50% below 1990 emissions levels by 2050. This would amount to just 18 billion tonnes of CO2 emissions annually. These kind of targets are seen as necessary for keeping global temperature rises below the 2°C level beyond which climate change would be dangerous. In 2050, the UN’s medium population growth scenario predicts 9 billion people on the planet, meaning that average emissions per person would be just 2 tonnes per year. Read the rest of this entry »

Saturday round-up: Melting ice speeds Arctic warming

The image shows satellite-derived Arctic surface temperature trends during autumn over the period 1981-2008. Greenland is on the right, North America at the bottom of the image, and Europe at the top. Warming has been enhanced over the Arctic Ocean due to the dramatic recent decline in sea ice cover. The brightest reds correspond to a 0.42°C rise over this period, while the blue-ish colours represent falling surface temperatures, up to a maximum of 0.10°C. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio.

The image shows satellite-derived Arctic surface temperature trends during autumn over the period 1981-2008. Greenland is on the right, North America at the bottom of the image, and Europe at the top. Warming has been enhanced over the Arctic Ocean due to the dramatic recent decline in sea ice cover. The brightest reds correspond to a 0.42°C rise over this period, while the blue-ish colours represent falling surface temperatures, up to a maximum of 0.10°C. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio.

Air temperatures near the Arctic surface have risen almost twice as much as the global average in recent decades – and melting sea ice is the main cause. This process will continue to accelerate, according to James Screen and Ian Simmonds of the University of Melbourne, who revealed their results in Thursday’s edition of Nature.

“The sea ice acts like a shiny lid on the Arctic Ocean,” Screen explains. “When it is heated, it reflects most of the incoming sunlight back into space. When the sea ice melts, more heat is absorbed by the water. The warmer water then heats the atmosphere above it. This feedback system has warmed the atmosphere at a faster rate than it would otherwise.” “It was previously thought that loss of sea ice could cause further warming,” adds Simmonds. “Now we have confirmation this is already happening.”

Read the rest of this entry »

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