Global warming has not stalled, insists world’s best-known climate scientist
Global mean surface temperature difference from the average for 1880–2009 (Photo credit: Wikipedia)
Suggestions that global warming has stalled are a “diversionary tactic” from “deniers” who want the public to be confused over climate change, according to the world’s best-known climate scientist. The Guardian reports Prof James Hansen, who first alerted the world to climate change in 1988, said on Friday: “It is not true that the temperature has not changed in the two decades.”
Since 1998, when the Niño climate phenomenon caused global temperatures to soar, the rate of increase in warming has slowed, causing some sceptics to suggest climate change has stopped or that the effect of rising carbon dioxide levels on climate is not as great as previously thought.
Prof Hansen, speaking to BBC Radio 4′s Today programme, rejected both arguments. “In the last decade it has warmed only a tenth of a degree compared to two-tenths of a degree in the preceeding decade, but that’s just natural variability. There is no reason to be surprised by that at all,” he said. “If you look over a 30-40 year period the expected warming is two-tenths of a degree per decade, but that doesn’t mean each decade is going to warm two-tenths of a degree: there is too much natural variability.”
Prof Hansen said the focus by some on “details” was a smokescreen. “This is a diversionary tactic. Our understanding of global warming and human-made climate change has not been affected at all,” he said. “It’s because the deniers [of the science] want the public to be confused. They raise these minor issues and then we forget about what the main story is. The main story is carbon dioxide is going up and it is going to produce a climate which is going to have dramatic changes if we don’t begin to reduce our emissions.” In 2008, scientists anticipated an upcoming slowing in temperature rises.
Prof Hansen, who recently stepped down from his Nasa post after almost 50 years to focus on communication, said the forecast impact of climate change was little affected by the recent slowdown in the rate of rising temperatures.
“Climate is a complicated system but there is no change at all in our understanding of climate sensitivity [to carbon dioxide] and where the climate is headed,” he said. “Our understanding of sensitivity is based on the Earth’s history, not on climate models, and we have good data on how the Earth responded in the past when carbon dioxide changed. So there is no reason to change the forecast for the long term.” On 9 May, a new study of lake sediments from a remote meteorite crater in Siberia showed temperatures in the region were 8C higher the last time CO2 levels were as high as they are today. Last week, atmospheric CO2 concentrations reached the milestone 400 parts per million, for the first time in millions of years.
Prof Hansen has caused controversy in the past with statements including “CEOs of fossil fuel companies should be tried for high crimes against humanity and nature” and the assertion that “coal-fired power plants are factories of death“.
Related articles
- Tom Zeller Jr.: Scientists Agree (Again): Climate Change Is Real (huffingtonpost.com)
- Study consensus for global warming (bigpondnews.com)
- Hansen Says Tar-Sands Oil Makes Climate Change Unsolvable – Bloomberg (bloomberg.com)
- AUDIO: Has global warming stalled? (bbc.co.uk)
EarthTalk: Climate Change and Hawaii’s Coral Reefs
English: Table coral of genus Acropora (Acroporidae) at French Frigate Shoals, Northwestern Hawaiian Islands (Photo credit: Wikipedia)
Despite sweeping protections put in place near the end of George W. Bush’s presidency for large swaths of marine ecosystems around the Hawaiian Islands, things are not looking good for Hawaii’s coral reefs. ENN reports
Poisonous run-off, rising ocean levels, increasingly acidic waters and overfishing are taking their toll on the reefs and the marine life they support. Biologists are trying to remain optimistic that there is still time to turn things around, but new threats to Hawaii’s corals are only aggravating the situation.
To wit, a previously undocumented cyanobacterial fungus that grows through photosynthesis is spreading by as much as three inches per week on corals along the otherwise pristine North Shore of Kauai. “There is nowhere we know of in the entire world where an entire reef system for 60 miles has been compromised in one fell swoop,” biologist Terry Lilley told The Los Angeles Times. “This bacteria has been killing some of these 50- to 100-year-old corals in less than eight weeks.” He adds that the strange green fungus affects upwards of five percent of the corals in famed Hanalei Bay and up to 40 percent of the coral in nearby Anini Bay, with neighboring areas “just as bad, if not worse.” Lilly worries that the entire reef system surrounding Kauai may be losing its ability to fend off pathogens.
Meanwhile, some 60 miles to the east across the blue Pacific, an invasive algae introduced for aquaculture three decades ago in Oahu’s Kaneohe Bay is also spreading quickly. Biologists are concerned because it forms thick tangled mats that soak up oxygen in the water needed by other plants and animals, in turn converting coral reefs there into smothering wastelands.
“This and other invasive algal species … don’t belong in Hawai’i,” says Eric Conklin, Hawaii director of marine services for The Nature Conservancy, which works to protect ecologically important lands and waters worldwide. He adds that there are not enough plant-eating fish to keep them under control.
Biologists are working hard to battle the algae in and around Kaneohe Bay. Conklin and his colleagues from the Conservancy have joined forces with researchers from the state of Hawaii to develop an inexpensive new technology, dubbed the Super Sucker, which uses barge-based hoses and pumps to vacuum the invasive algae away without disturbing the underlying coral.
Related articles
- Coral Reefs (livescience.com)
- Coral Reef Collapse Not Inevitable: Ecosystem in Danger, Not Doomed (scienceworldreport.com)
- Coral Reefs (rkarryel.wordpress.com)
CLIMATE CHANGE : Floods could overwhelm London as sea levels rise – unless Thames Barrier is upgraded
The Thames Flood Barrier in 2005 (Photo credit: Wikipedia)
Having previous lived on London‘s outskirts for some years, this news is disturbing!
There is significant risk of London being hit by a devastating storm surge in the Thames estuary by 2100 that could breach existing flood defences and cause immense damage to the capital, a study of global sea-level rise has found. The Independent reports
Melting of polar ice sheets and mountain glaciers could increase sea levels significantly over the coming decades leading to a 1 in 20 risk that the existing Thames Barrier would be unable to cope with an extreme storm surge, the study concluded.
Extreme storm surges that can breach the barrier would in the past have occurred with a frequency of about 1 in 1,000 years, but in a warmer world they could occur as frequently as 1 in every 10 years, scientists said.
The increased threat posed by rising sea levels is one of the reasons why flood defences around the Thames estuary and the barrier itself will be strengthened.
English: This graphic describes the sea-level rise. (Photo credit: Wikipedia)
An international panel of glaciologists and climate scientists said there is still huge uncertainty about how sea levels will change in the coming century as a result of climate change and its effect on polar ice sheets and mountain glaciers.
Their best estimate is that the melting ice on its own will contribute between 3.5cm and 36.8cm to mean sea levels, which would come on top of the rise in sea level due to other factors such as the thermal expansion of the warmer oceans.
However, there is a 1 in 20 risk of this being a wild underestimate and that melting polar ice and mountain glaciers alone would contribute more than 84cm to global sea level, which would lead to rises of about a metre around Britain if other factors are taken into account, they said.
“The Thames Barrier was built to provide London with a level of protection that would only be exceeded in about 1 in every 1,000 years. So in any one year the likelihood of exceeding this is about 0.1 per cent,” said Professor David Vaughan of the British Antarctic Survey.
“With 50cm of sea level rise we would expect that level of protection to go down from 1 in 1,000 years to about 1 in 100 years, so under that scenario in every year there would be a 1 per cent chance of flooding. If you have a metre rise you go down from 1 in 1,000 years to 1 in 10 years,” Professor Vaughan said.
These estimates are based on existing “business as usual” emissions of carbon dioxide, leading to about a 3.5C rise in mean global temperature by 2100. Greater emissions would lead to higher temperatures and faster melting, the scientists said.
How sea-level rise and polar ice sheets will respond to rising temperatures is one of the greatest uncertainties in climate science. The research programme, called Ice 2 Sea, was established by the UN’s Intergovernmental Panel on Climate Change to estimate the future contribution to sea level from melting ice.
“There is still extra uncertainty that arises because our models are not complete. There are still processes that we think are important but we haven’t been able to include in our models,” said Professor Vaughan, the coordinator of the programme.
The scientists carried out “expert elicitation” among themselves to take into account the unknowns that their computer models were unable to include, Professor Vaughan said.
“That has come up with this number: there is less than a 1 in 20 risk of ice sheets and glaciers contributing more than 84cms to sea level rise by 2100. That is trying to capture those climate processes that we suspect are important yet are not fully included in existing models,” he said.
Sea levels would rise by varying degrees around the world due to melting ice, and would even decline in areas around Greenland and Antarctica due to the diminished gravitational pull of the dwindling ice sheets. The British coastline would see sea level rises that are slightly below the global average, Professor Vaughan said.
“It is likely that some future ice loss and sea level rise is now unavoidable. But nevertheless, understanding why changes are occurring today and how they could increase in the future is the first step in maintaining the security of our coastal regions for future generations,” he said.
Related articles
- ‘Best estimate’ of melting ice caps (bbc.co.uk)
- Floods could ‘overwhelm Thames Barrier by end of century’ (guardian.co.uk)
- Risk to London from rising seas ‘worse than feared’ (thetimes.co.uk)
- Claim: Sea levels in Europe could rise up to 1m by 2100 (junkscience.com)
- Experts say rapidly melting glaciers are raising the UK flood risk (itv.com)
- The beginning of the end: warmists in retreat on sea level rise, climate sensitivity (wattsupwiththat.com)
CLIMATE CHANGE : Global carbon dioxide in atmosphere passes milestone level
Mean surface temperature change for 1999–2008 relative to the average temperatures from 1940 to 1980 (Photo credit: Wikipedia)
For the first time in human history, the concentration of climate-warming carbon dioxide in the atmosphere has passed the milestone level of 400 parts per million (ppm). The Guardian reports
The last time so much greenhouse gas was in the air was several million years ago, when the Arctic was ice-free, savannah spread across the Sahara desert and sea level was up to 40 metres higher than today.
These conditions are expected to return in time, with devastating consequences for civilisation, unless emissions of CO2 from the burning of coal, gas and oil are rapidly curtailed. But despite increasingly severe warnings from scientists and a major economic recession, global emissions have continued to soar unchecked.
“It is symbolic, a point to pause and think about where we have been and where we are going,” said Professor Ralph Keeling, who oversees the measurements on a Hawaian volcano, which were begun by his father in 1958. “It’s like turning 50: it’s a wake up to what has been building up in front of us all along.”
“The passing of this milestone is a significant reminder of the rapid rate at which – and the extent to which – we have increased the concentration of greenhouse gases in the atmosphere,” said Prof Rajendra Pachauri, chair of the Intergovernmental Panel on Climate Change, which serves as science adviser to the world’s governments. “At the beginning of industrialisation the concentration of CO2 was just 280ppm. We must hope that the world crossing this milestone will bring about awareness of the scientific reality of climate change and how human society should deal with the challenge.”
The world’s governments have agreed to keep the rise in global average temperature, which have already risen by over 1C, to 2C, the level beyond which catastrophic warming is thought to become unstoppable. But the International Energy Agency warned in 2012 that on current emissions trends the world will see 6C of warming, a level scientists warn would lead to chaos. With no slowing of emissions seen to date, there is already mounting pressure on the UN summit in Paris in 2015, which is the deadline set to settle a binding international treaty to curb emissions.
Edward Davey, the UK’s energy and climate change secretary, said: “This isn’t just a symbolic milestone, it’s yet another piece of clear scientific evidence of the effect human activity is having on our planet. I’ve made clear I will not let up on efforts to secure the legally binding deal the world needs by 2015 to avoid the worst effects of climate change.”
Two CO2 monitoring stations high on the Hawaiian volcano of Mauna Loa are run by the US National Oceanic and Atmospheric Administration and the Scripps Institution of Oceanography and provide the global benchmark measurement. Data released on Friday shows the daily average has passed 400ppm for the first time in its half century of recording. The level peaks in May each year as the CO2 released by decaying vegetation is taken up by renewed plant growth in the northern hemisphere, where the bulk of plants grow.
Analysis of fossil air trapped in ancient ice and other data indicate that this level has not been seen on Earth for 3-5 million years, a period called the Pliocene. At that time, global average temperatures were 3 or 4C higher than today’s and 8C warmer at the poles. Reef corals suffered a major extinction while forests grew up to the northern edge of the Arctic Ocean, a region which is today bare tundra.
“I think it is likely that all these ecosystem changes could recur,” said Richard Norris, a colleague of Keeling’s at Scripps. The Earth’s climate system takes time to adjust to the increased heat being trapped by high greenhouse levels and it may take hundreds of years for the great ice caps in Antarctica and Greenland to melt to the small size of the Pliocence and sea level far above many of the world’s major cities.
But the extreme speed at which CO2 in now rising – perhaps 75 times faster than in pre-industrial time – has never been seen in geological records and some effects of climate change are already being seen, withextreme heatwaves and flooding now more likely. Recent wet and cold summer weather in Europe has been linked to changes in the high level jetstream winds, in turn linked to the rapidly melting sea ice in the Arctic, which shrank to its lowest recorded level in September.
“We are creating a prehistoric climate in which human societies will face huge and potentially catastrophic risks,” said Bob Ward, policy director at the Grantham Research Institute on Climate Change at the London School of Economics. “Only by urgently reducing global emissions will we be able to avoid the full consequences of turning back the climate clock by 3 million years.”
“The 400ppm threshold is a sobering milestone and should serve as a wake up call for all of us to support clean energy technology and reduce emissions of greenhouse gases, before it’s too late for our children and grandchildren,” said Tim Lueker, a carbon cycle scientist at Scripps.
Professor Bob Watson, former IPCC chair and UK government chief scientific adviser, said: “Passing 400ppm of carbon dioxide in the atmosphere is indeed a landmark and the rate of increase is faster than ever and shows no sign of abating due to a lack of political committment to address the urgent issue of climate change – the world is now most likely committed to an increase in surface temperature of 3C-5C compared to pre-industrial times.”
The graph of the rising CO2 at Mauna Loa is known as the Keeling curve, after the late Dave Keeling, the scientist who began the measurements in March 1958. The isolated Hawaiian island is a good location for measurements as it is far from the main sources of CO2, meaning it represents a good global average.
Related articles
- Climate Milestone: Earth’s CO2 Level Nears 400 ppm (news.nationalgeographic.com)
- Carbon dioxide at NOAA’s Mauna Loa Observatory reaches new milestone: Tops 400 parts per million (sciencedaily.com)
- 400 ppm …. yikes! (skeptical-science.com)
- Climate: Atmospheric CO2 reaches 400 ppm (summitcountyvoice.com)
Climate change compounds rising threats to koala
centre (Photo credit: Wikipedia)
Australia’s iconic marsupial is under threat. Formerly hunted almost to extinction for their woolly coats, koalas are now struggling to survive as habitat destruction caused by droughts and bushfires, land clearing for agriculture and logging, and mining and urban development conspire against this cuddly creature.
In the past 20 years, the koala population has significantly declined, dropping by 40 percent in the state of Queensland and by a third in New South Wales (NSW). The Australian Koala Foundation (AKF) estimates that there are between 45,000 and 90,000 koalas left in the wild.
Shrinking habitat and climate change is compounding the risk of disease, while attacks from feral and domestic dogs and road accidents add to a long list of risks that this arboreal mammal faces as it moves across the landscape in search of food.
It is estimated that around 4,000 koalas are killed each year by dogs and cars alone.
Climate scientists warn that forecasts of longer dry periods, rises in temperature, more intense bushfires and severe droughts pose a significant risk to the koala, which is endemic only to Australia.
“In the past decade, we have experienced the hottest temperatures on record followed by floods and cyclones. The koalas are highly susceptible to heat stress and dehydration,” University of Queensland koala expert Dr. Clive McAlpine told IPS.
“Our climate envelope modelling found that koalas occur at a maximum temperature of 37.7 degrees centigrade. Across western Queensland and New South Wales, temperatures remained in the mid to high 40-degree centigrade (range) for consecutive days, pushing them beyond their climatic threshold.”
The name koala is derived from the aboriginal word meaning “no drink”, as the creatures feed on and derive much of their moisture needs from the nutrient-poor eucalyptus leaves. An individual Koala may have to consume 500 grammes of leaves or more each day in order to grow and survive.
“Climate-induced changes will not only reduce their food resource, but also the nutritional quality and moisture content of leaves. Most recently an 80 percent decline was documented in Queensland’s Mulga Lands following the 10-year drought,” McAlpine told IPS.
According to the AKF, protecting the existing koala eucalypt forests is also an imperative step towards reducing greenhouse emissions in Australia. Since 1788, nearly 65 percent (116 million hectares) of the koala forests have been cleared and the remaining 35 percent (41 million hectares) remains under threat from land clearing for agriculture, urban development and unsustainable forestry.
As koalas and humans vie for space amidst growing urban and infrastructure development on Australia’s eastern seaboard, koalas have been venturing out of their confined eucalyptus forest habitat, often crossing major roads in search of trees or mates.
“Koalas’ continuous move into urban areas makes them highly vulnerable to road (accidents) and attacks by dogs. In the rapidly developing region of southeast Queensland, the species has suffered a 60 percent decline in the past decade due to the combination of disease, dog attacks, but mostly collisions with cars,” Darryl Jones, deputy director of the Environmental Futures Centre at the Queensland-based Griffith University, told IPS.
Jones, who is the lead author of a recent study aimed at assisting the safe movement of koalas, said, “When forced out of their natural habitat, koalas use all resources available to them including backyard trees, tree-lined road verges and median strips. Retention of these marginal habitats in urban areas is important for koala movement and dispersal.”
Australia’s Wildlife Information, Rescue and Education Service (WIRES) recently rescued a confused sub-adult male koala from the middle of a felled pine forest in NSW. He was sitting on top of a woodchip pile, with trucks and machinery operating close by.
WIRES General Manager Leanne Taylor said, “If koalas are moved out of their homes in preparation for planned logging activities, it is common for them to roam back to their home range afterwards and become confused to find nothing there.”
Koala advocacy groups say the government is putting mining interests above the environment. According to a spokesperson for the Wilderness Society, “Koala habitat is facing additional threat from expanding coal mining and coal seam gas operations, tree kills from coal seam gas spills, and increased infrastructural and vehicular traffic that comes with mining development. It is putting extra strain on the already declining koala populations in New South Wales and Queensland.”
The Australian Government last year listed the koala as “vulnerable” under the Environment Protection and Biodiversity Conservation Act of 1999 on the recommendation of the Threatened Species Scientific Committee.
“It has taken 17 years of campaigning to get this listing and conservation groups like ours believe that in some regions the species requires a ‘critically endangered’ listing,” David Burgess, natural areas campaigner at the Total Environment Centre in Sydney, told IPS.
Deborah Tabart, CEO of the AKF, told IPS, “The protection does not go far enough and the Federal Government has underestimated the danger koalas face. We urgently need a Koala Protection Act.”
The International Union for Conservation of Nature (IUCN) lists the koala as “potentially vulnerable”. In 2000, the U.S. Fish and Wildlife Service listed the koala as “threatened” under the United States Endangered Species Act.
Two other deadly threats to the koalas’ survival are chlamydia, a sexually transmitted disease, and the koala retrovirus (KoRV), an HIV-like virus. According to some estimates, around half of all Australia’s koalas are infected with a strain of chlamydia, which causes infertility, blindness, respiratory and urinary infections and death.
Chlamydia affects male and female koalas, and even joeys who pick up the infection while suckling from their mother in the pouch. In some parts of Australia, koala infection rates are as high as 90 percent.
With a life span of between 10 and 14 years, koalas are slow breeders and usually produce one joey a year.
A joint team of researchers from the Australian Museum and the Queensland University of Technology have recently sequenced the koala interferon gamma (IFN-g) gene, a discovery that they call the “holy grail” for understanding the koala immune system. They are currently trialling a vaccine to protect koalas from chlamydia.
The government has formulated a National Koala Conservation and Management Strategy 2009 – 2014. But conservation groups say the major threat to the koala is inaction, lack of resources and willpower from both national and state governments.
Burgess warns, “Unless meaningful action is taken to protect the koala habitat, it may get to the point where the species relies on expensive captive breeding programmes for its survival.”
Related articles
- Australia’s koala crisis: gene sequencing provides hope against killer diseases (guardian.co.uk)
- Chlamydia Is Killing Koalas – Will Genetics Find a Cure? (blogs.scientificamerican.com)
- Genome the blueprint for saving koala (nzherald.co.nz)
Recent Comments