Category Archives: Warming

Outlook palls for fossil fuel investments

Fuelling controversy: Coal being loaded onto a train in Queensland, Australia Image Ellis678 via Wikimedia Commons
Fuelling the controversy: coal being loaded onto a train in Queensland, Australia
Image Ellis678 via Wikimedia Commons

By Kieran Cooke

Warnings within the world of high finance are coming thick and fast that the increasingly urgent need to combat climate change means investors could lose heavily by sinking funds into coal, oil and gas.

LONDON, 18 October, 2014 − Like most central bank governors, Mark Carney, the Governor of the Bank of England, chooses his words carefully.

So the financial community – and government policy makers − sat up and took notice earlier this month when Carney, addressing a World Bank seminar on corporate reporting standards, said he was concerned about investments in fossil fuels.

“The vast majority of reserves are unburnable,” Carney said.

‘Tragedy of horizons’

He warned companies, investors and policy makers that they need to avoid what he described as the “tragedy of horizons”, and to look further ahead to meet challenges such as climate change.

Investors are being repeatedly told that money sunk into fossil fuels is not only bad for the climate, but is also potentially seriously dangerous to financial health.

The fundamental idea espoused by a wide spread of influential voices – ranging from the International Energy Association (IEA) to finance funds that have many billions of dollars worth of investments under their control − is that, in order to combat climate change, a large portion of the world’s remaining fossil fuel reserves must stay in the ground.

“Not more than one-third of proven reserves of fossil fuels can be consumed prior to 2050 if the world is to achieve the 2˚C goal,” the IEA says.

Limiting a rise in average global temperatures to 2˚C by mid-century is considered to be the minimum necessary to prevent catastrophic climate change.

As action is taken and regulations are tightened, investments in fossil fuels, whether in a coal mine or in oil or gas exploration and production, will become frozen – or, in the parlance of the finance industry, “stranded”.

In the lead up to a major UN conference on climate change in New York last month, a group of high-roller investment funds − which, together, control more than $24 trillion worth of assets – called for an end to fossil fuel subsidies and for urgent action on climate change.

“We’re not going to be able to burn
it all. Science is science”

Barack Obama, the US president, has joined in the chorus, calling for fossil fuels to stay in the ground. “We’re not going to be able to burn it all,” Obama said earlier this year. “Science is science. And there is no doubt that if we burned all fossil fuels that are in the ground right now that the planet’s going to get too hot, and the consequences could be dire.”

Major campaigns calling for divestment from fossil fuels have been launched. Groups such as 350.org, which campaigns for more awareness on climate issues, have had considerable success in persuading various bodies – from universities to the UK’s leading medical association − to stop investing in fossil fuels.

A number of pension funds, with billions of dollars worth of investments under their control, have said they will either cut back or stop putting money into the fossil fuel industry.

Public pressure

Meanwhile, giant coal, oil and gas corporations have been told they could face a public backlash if they seek to avoid or deny public pressure on climate change issues.

But for those who want to see an end to the fossil fuel industry, the battle is by no means won. It is only just starting.

A report by the Carbon Tracker Initiative and the Grantham Research Institute on Climate Change and the Environment says the world’s 200 largest publicly-quoted fossil fuel companies spent an estimated total of $674bn on exploring and developing new reserves in 2012. And that figure does not include the hundreds of billions of dollars spent on exploiting existing fossil fuel sites.

Coal, the most polluting of fossil fuels, is still king in many regions of the world, particularly in the fast-growing economies of China and India. Coal companies, urged on by politicians, are still investing billions in new facilities.

Tony Abbott, Australia’s prime minister, opening a huge new mine in Queensland that will produce about 5.5 million tonnes of coal each year, said last week: “Coal is vital for the future energy needs of the world. So let’s have no demonisation of coal – coal is good for humanity.” – Climate News Network

Ice loss sends Alaskan temperatures soaring

Scientists studying Arctic sea ice and melt ponds on the Chuckchi Sea Image: NASA/Kathryn Hansen
Melting point: researchers study Arctic sea ice and melt ponds on the Chuckchi Sea
Image: NASA/Kathryn Hansen via Wikimedia Commons

By Alex Kirby

Scientists analysing more than three decades of weather data for the northern Alaska outpost of Barrow have linked an astonishing 7°C temperature rise to the decline in Arctic sea ice.

LONDON, 17 October, 2014 − If you doubt that parts of the planet really are warming, talk to residents of Barrow, the Alaskan town that is the most northerly settlement in the US.

In the last 34 years, the average October temperature in Barrow has risen by more than 7°C − an increase that, on its own, makes a mockery of international efforts to prevent global temperatures from rising more than 2°C above their pre-industrial level.

A study by scientists at the University of Alaska Fairbanks analysed several decades of weather information. These show that temperature trends are closely linked to sea ice concentrations, which have been recorded since 1979, when accurate satellite measurements began.

The study, published in the Open Atmospheric Science Journal, traces what has happened to average annual and monthly temperatures in Barrow from 1979 to 2012.

Most striking

In that period, the average annual temperature rose by 2.7°C. But the November increase was far higher − more than six degrees. And October was the most striking of all, with the month’s average temperature 7.2°C higher in 2012 than in 1979.

Gerd Wendler, the lead author of the study and a professor emeritus at the university’s International Arctic Research Center, said he was “astonished”. He told the Alaska Dispatch News: “I think I have never, anywhere, seen such a large increase in temperature over such a short period.”

The study shows that October is the month when sea ice loss in the Beaufort and Chukchi Seas, which border northern Alaska, has been highest. The authors say these falling ice levels over the Arctic Ocean after the maximum annual melt are the reason for the temperature rise. “You cannot explain it by anything else,” Wendler said.

They have ruled out the effects of sunlight because, by October, the sun is low in the sky over Barrow and, by late November, does not appear above the horizon.

Instead, they say, the north wind picks up stored heat from water that is no longer ice-covered in late autumn and releases it into the atmosphere.

At first sight, the team’s findings are remarkable, as Barrow’s 7.2°C rise in 34 years compares with a global average temperature increase over the past century of up to about 0.8°C. But what’s happening may be a little more complex.

Warming faster

The fact that temperatures in and around Barrow are rising fast is no surprise, as the Arctic itself is known to be warming faster than most of the rest of the world.

The Intergovernmental Panel on Climate Change says observed warming in parts of northern Alaska was up to 3°C from the early 1980s to the mid-2000s. It also concludes that about two-thirds of the last century’s global temperature increase has occurred since 1980.

But Barrow’s long-term temperature rise has not been uniform, the Fairbanks study says. Its analysis of weather records between 1921 and 2012 shows a much more modest average annual rise, of 1.51°C. In 2014, the city experienced the coolest summer day recorded − 14.5°C.

So one conclusion is to remember just how complex a system the climate is − and how even 34 years may be too short a time to allow for any certainty. − Climate News Network

Australia gets early blast of more extreme heat

A bushfire rages in the hills near Lithgow, New South Wales, last year Image: Lithgowlights via Wikimedia Commons
Hot spot: a bushfire rages in the hills close to Lithgow, New South Wales, last year
Image: Lithgowlights via Wikimedia Commons

By Kieran Cooke

Summer has come early across much of Australia – and as temperatures soar to record seasonal levels in many areas, the bushfire season has started well ahead of schedule.

LONDON, 14 October, 2014 − It’s the time of year when many Australians start to think about eating outdoors or heading for the beach after work. Early spring, and the temperatures are rising – particularly this year.

The Australian Government’s Bureau of Meteorology (BOM) says maximum temperatures in September across much of the country were higher than average, with central and south-western areas experiencing their warmest September on record.

Australia is considered to be particularly vulnerable to the effects of a climate change, and 2013 was the country’s hottest year since records began, with average temperatures 1.2˚C above the long-term average.

In one seven-day period in early January last year, record national average temperatures exceeded 39˚C.

Unprecedented levels

September started off cool in Sydney, Australia’s most populated city, but then heated up to unprecedented levels for this time of year. For the first time, temperatures climbed to more than 32˚C for two consecutive days in the month.

Meanwhile, overall September rainfall was 27% below the monthly average − and the dry conditions mean the bushfire season has come early. The south of the island of Tasmania has fared particularly badly, with fires fuelled by dry conditions and high winds.

Areas round Sydney and throughout New South Wales – the country’s most populous state − have also been hit by bushfires, with fire warnings going out to more than a million homeowners.

Despite growing evidence that human-induced climate change is a major reason for Australia heating up, the Liberal-National coalition government led by Prime Minister Tony Abbott has taken little action on the issue.

It has abolished a carbon tax introduced by the previous Labour government, abolished a Climate Commission that gave advice on the impact of warming, and is seeking to downgrade modest renewable energy targets.

Polluting fuel

Australia is one of the world’s leading producers of coal – the most polluting fuel, which is responsible for a significant portion of climate changing greenhouse gas emissions (GHGs). The country’s per capita GHG emissions are among the highest in the world.

A recent report on Australia’s climate, produced by BOM and the Commonwealth Scientific and Industrial Research Organisation (CSIRO), the national science agency, predicts temperatures rising across the country by between 0.6˚C and 1.5C by 2030, compared with the rise of 0.6˚C between 1910 and 1990.

The report says: “Data and analysis from BOM and CSIRO show further warming of the atmosphere and oceans in the Australian region. . . this warming has seen Australia experiencing warm weather and extreme heat, and fewer cool extremes.

“There has been an increase in extreme fire weather, and a longer fire season, across large parts of Australia.” – Climate News Network

Solar dimming reflects complexity of climate change

 

Ominous signs: monsoon clouds roll in over Visakhapatnam in south-east India Image: Adityamadhav83 via Wikimedia Commons
Monsoon clouds roll in over Visakhapatnam, south-east India, but rainfall is reducing
Image: Adityamadhav83 via Wikimedia Commons

By Tim Radford

Reduced monsoon rainfall and increased river flow are two extremes that new research has linked to man-made impacts on climate caused by air pollution.

LONDON, 13 October, 2014 − Two separate studies have confirmed the extent of human influence on climate change – and, for once, carbon dioxide is not the usual suspect.

One team has just found that air pollution dimmed the skies of northern Europe, reflected sunlight back into space, reduced evaporation, and increased river flow.

The second group reports that similar aerosol pollution had a quite different effect on the Asian monsoons: in the second half of the 20th century, the darkening skies reduced temperatures and cut the summer monsoon rainfall by 10%.

The two seemingly contradictory findings underscore two clear conclusions. One is that climate science is complex. The other is that human activity clearly influences the climate in different ways.

Worldwide concern

Both studies are concerned with an era when there was, worldwide, more concern about choking smog, sulphuric aerosol discharges and acid rain than about man-made global warming. They also both match complex computer simulation with observed changes in climate during the second half of the 20th century

Nicola Gedney, a senior scientist at the UK’s Meteorological Office, and colleagues report in Nature Geoscience that she and colleagues looked at the growth in aerosol pollution, especially in the Oder river catchment area of central-eastern Europe, that followed the increased burning of sulphurous coal in Europe right up till the late 1970s.

The consequence of that burning was a reduction in sunlight over the hemisphere. But this began to reverse with clean air legislation and a widespread switch to cleaner fuels. River flows, which had been on the increase, were reduced.

“We estimate that, in the most polluted central Europe river basin, this effect led to an increase in river flow of up to 25% when the aerosol levels were at their peak, around 1980,” Dr Gedney said. “With water shortages likely to be one of the biggest impacts of climate change in the future, these findings are important in making projections.”

Aerosol pollution

Meanwhile, a group led by Debbie Polson, a researcher in the University of Edinburgh’s School of Geosciences, Scotland, focused on aerosol pollution and the Asian summer monsoons, which provide four-fifths of the annual rainfall of the Indian subcontinent.

They report in Geophysical Research Letters that they calculated annual summer rainfall between 1951 and 2005, used computer simulations to quantify the impact of increasing aerosol emissions and greenhouse gases during that time, and factored in natural variations, such as volcanic discharges.

They found that, overall, levels of rain during the monsoon fell by 10%, and this change could only be explained by the influence of aerosols from car and factory exhausts.

“This study has shown for the first time that the drying of the monsoon over the past 50 years cannot be explained by natural climate variability, and that human activity has played a significant role in altering the seasonal monsoon rainfall on which billions of people depend,” Dr Polson said. – Climate News Network

Croppers pose new threat to Amazon rainforest

Palm oil is well placed to grow faster than any other commodity in Brazil Image: Marco Schmidt via Wikimedia Commons
Growing threat: palm oil is well placed to grow faster than any other commodity in Brazil
Image: Marco Schmidt via Wikimedia Commons

By Alex Kirby

Analysts in the US say parts of the Brazilian Amazon may face new deforestation as ranchers move from raising beef cattle to cultivating crops such as palm oil.

LONDON, 12 October, 2014 − Despite Brazil having made great strides in reducing logging in the Amazon region, a US study says the country faces a renewed threat to its forests.

The report’s authors − who focused on the Amazon states of Mato Grosso and Pará, where they interviewed ranchers and meat processors − say the cost of raising beef cattle is prompting many ranchers to consider switching to crops such as palm oil.

The study by Datu Research, a global economic research firm based in Washington DC. was commissioned by the Environmental Defense Fund.

After decades of deforestation, it says, efforts to curb the losses have been working. Between 2005 and 2013, the rate of loss fell by nearly 80% − although  the Brazilian government’s figures show that losses rose again by 29% in the year to 31 July 2013.

The beef industry, meanwhile, which had caused nearly 75% of earlier deforestation, has continued to grow rapidly.

Curb on emissions

Researchers have argued that by taxing cattle on conventional pasture and by subsidising semi-intensive cattle rearing, Brazil could curb up to 26% of the global greenhouse gas (GHG) emissions caused by the loss of forests. This in turn adds up to about one-fifth of all human-caused GHG emissions.

But the forests face problems from another quarter. The authors of the Datu Research study say pressure from Western companies requiring deforestation-free supply chains for beef from the Amazon risks being overwhelmed by big increases in demand from non-Western countries.

Russia’s recent embargo of Western beef, for example, means it has increased its demand for Brazilian beef by over 10%, creating alternative markets that do not require deforestation-free operations.

The amalgamation of the meat processors has reduced the ranchers’ bargaining power. The market share of the three largest processors − JBS, Marfrig and Minerva − grew from 24% in 2011 to 37% in 2013.

The study’s authors also say many small and medium-size processors report that, unlike their big competitors, they have restricted access to finance, which reduces their ability to monitor deforestation.

Poor regulation of cattle-raising is another problem − expensive for those ranchers who comply with the rules, yet allowing those who ignore them to escape with impunity. Licensing agencies sometimes lose entire applications, and illicit cattle operations can still enter legitimate supply chains.

Falsified documents showing the origin
and destination of cattle are easily obtained

It is not difficult, the report says, to circumvent a system that is meant to track cattle from ranch to slaughterhouse. Falsified documents showing the origin and destination of cattle are easily obtained, and cost as little as R$200 (about US$85).

A major factor in prompting ranchers to fell the forests is the harsh economic dilemma they face. The study found that the cost of going deforestation-free on 145 hectares is R$412,000 (US$167,000), nearly double the R$217,500 cost of simply clearing forest for beef production.

And while newly-deforested land can sustain cattle for at least five years at no further cost, managing pasture properly is expensive because it needs fertilizers, machinery and other investments, which cost about R$50,000 annually.

Land tenure is another problem. Several ranchers told the authors they had been waiting, sometimes for more than 20 years, to receive legal title to their land. Without a title, banks will not lend ranchers the money they need to change to a deforestation-free operation.

Foreign demand

The study found that deforestation driven by land speculation is increasing rapidly in Brazil. A further concern is the growing foreign demand for a range of crops whose cultivation requires the removal of trees. The Federation of the Industries of the State of São Paulo says production of four crops alone − soya, corn (maize), sugarcane and palm oil − will need more than 10.5 m more hectares of land by 2023.

Palm oil is fairly new in Brazil, but it is well placed to grow faster than any other commodity. The government of Pará estimates that, by 2022, palm oil plantations for biofuel will cover 700,000 ha, which would make Brazil the world’s third largest producer, behind Indonesia and Malaysia.

The study says that that only already-degraded land should be used for palm oil, so that producers do not end up illegally clearing new land.

Deforestation in the Amazon region has a considerable impact on the world’s climate as the forest is a vital carbon “sink”, soaking up greenhouse gases. If it stopped acting as a sink and became instead a source of carbon, the consequences could be profound. − Climate News Network

‘Amazon of UK’ being destroyed for grouse shooting

Killing fields: A grouse shooting party sets out on the North Yorkshire moors in the UK Image: geograph.co.uk via Wikimedia Commons
Killing fields: a grouse shooting party sets out on the North Yorkshire moors in the UK
Image: geograph.co.uk via Wikimedia Commons

By Paul Brown

Managing moorlands so that more birds can be reared for lucrative shooting parties is adding to climate change by destroying layers of peat and releasing large quantities of stored carbon dioxide into the atmosphere.

LONDON, 6 October, 2014 − Burning large tracts of heather on the peat-covered hills of Britain so that more red grouse can be reared for the rich to shoot has always been controversial.

The revenue from overseas visitors flying in from such places as the Middle East and Japan to shoot birds has long been used by the country estate owners to justify the practice.

But the first definitive scientific report into the effects that burning heather has on wildlife and climate change shows the damage to the environment is far worse than previously thought. The water run-off from the damaged peat also adversely affects the aquatic life in the rivers that drain the moorlands of Britain.

The report was released to coincide with start of the moorland burning season in Britain, when gamekeepers set fire to large areas of old heather in order to encourage new growth next year to feed chicks that will be shot in the autumn.

Britain contains 75% of the world’s remaining heather moorland, and its owners say that without the revenue from grouse shooting it would disappear.

Significant findings

The EMBER report (Effects of Moorland Burning on the Ecohydrology of River basins)  is the result of five years work by a team from Leeds University in the north of England, which is a popular area for shooting grouse.

Among the significant findings was that burning heather dried out and warmed the peat it grows in, causing the peat to disintegrate and release large quantities of stored carbon dioxide − so adding to the perils of climate change.

Professor Joseph Holden, from the School of Geography at the University of Leeds and co-author of the study, said: “Altering the hydrology of peatlands so they become drier is known to cause significant losses of carbon from storage in the soil.

“This is of great concern, as peatlands are the largest natural store for carbon on the land surface of the UK and play a crucial role in climate change. They are the ‘Amazon of the UK’.”

The EMBER project − funded by the Natural Environment Research Council, with additional support from the Yorkshire Water treatment and supply utility − assessed the impacts of heather burning on moorland consisting mainly of peat on higher land.

It compared 120 patches of peat in 10 river catchment areas across the English Pennines, with an equal split between burned and unburned areas. The area studied spanned from near Ladybower Reservoir in Derbyshire to Moor House National Reserve, which straddles the border between Cumbria and County Durham.

The red grouse is a major target during the shooting season. Image: Trish Steel via Wikimedia Commons
The red grouse is a major target during the shooting season
Image: Trish Steel via Wikimedia Commons

Among the numerous important findings of the EMBER project, the researchers discovered that the water table depth – the level below which the ground is saturated with water – is significantly deeper in areas where burning has taken place, compared to unburned areas.

A deeper water table means that the peat near the surface will dry out and degrade, releasing stored pollutants, such as heavy metals into rivers, and carbon into the atmosphere.

Other important findings from EMBER include a decrease in the diversity and population sizes of invertebrates, such as insect larvae, in rivers draining from burned areas, and up to a 20˚C increase in soil temperature in the immediate years after burning, compared to unburned sites.

Dr Brown said: “Even small changes in soil temperature can affect the decomposition of organic matter and the uptake of nutrients by plants. But we found increases as high as 20˚C, with maximum temperatures reaching over 50˚C in some cases.

“Such changes in thermal regime have not previously been considered in the debate over moorland management with fire, but could explain a lot of the changes we see in terms of soil chemistry and hydrology following burning.”

Dr Sheila Palmer, also from the School of Geography at the University of Leeds, and a co-author of the report, concludes: “Our hope is that the EMBER project findings will help all parties involved in assessing the range of benefits and impacts of moorland burning to work together in developing policies for the future management of our uplands.”

However, the Moorland Association, which represents the shooting estates, defended the practice of heather burning to promote greater numbers of grouse.

In a statement, the Association said: “Heather is kept young and vigorous by controlled burning. If left unburned, it eventually grows long and lank, reducing its nutritional value.

Burning cycle

“The burning cycle creates a pattern of different-aged heather. The oldest provides cover for the grouse and other birds; the new shoots, succulent food for birds and sheep. A skilfully burnt moor will have a mosaic of heather and other moor plants of differing ages and the rich variety of wildlife they attract.”

The association says that mowing heather is an alternative to burning, but not always possible because of rough terrain. It is also more expensive.

André Farrar, planning and strategy manager at the Royal Society for the Protection of Birds, which has long campaigned for the end of burning heather and the destruction of wildlife to promote grouse shooting said: “Managed burning has a profound impact on the life support systems of the peatlands in our hills.

“This supports the need to phase out and stop burning on deep peat soils in the uplands. It should also trigger a concerted effort to agree how to bring these special places back into better condition, involving Government, its agencies, and landowners.” – Climate News Network

Human handprint marks Australia’s hottest year

Australian weather stations recording temperatures of 45°C or above in January 2013 Image: Squidman18559 via Wikimedia Commons
Australian weather stations recording temperatures of 45°C or above in January 2013
Image: Squidman18559 via Wikimedia Commons

By Tim Radford

Despite the Australian prime minister’s climate science scepticism, research funded by taxpayers has unanimously found man-made climate change guilty of causing the country’s record-breaking temperatures last year.

LONDON, 4 October, 2014 − Scientists are fond of saying that it is difficult to pin the blame for any one climate event onto climate change. But they have just made an exception by reporting that many things that happened in Australia in 2013 bore the signature of man-made climate change.

In that one year, Australia recorded its hottest day ever, its hottest month in the history books, its hottest summer, its hottest spring, and its hottest year overall.

Extreme events

And in a special edition of the Bulletin of the American Meteorological Society, examining extreme events around the world during 2013, a series of papers home in on the Australian heat waves, and identify a human influence.

“We often talk about the fingerprint of human-caused climate change when we look at extreme weather patterns,” said David Karoly, professor of meteorology at the University of Melbourne’s School of Earth Sciences. “This research across four different papers goes well beyond that.

“If we were climate detectives, then Australia’s hottest year on records in 2013 wasn’t just a smudged fingerprint at the scene of the crime, it was a clear and unequivocal handprint showing the impact of human-caused global warming.”

In general, the world’s meteorologists have found nothing unequivocal to suggest that global warming due to greenhouse gas emissions from fossil fuel combustion caused, for example, the Californian drought, extreme snow in the Spanish Pyrenees or an October blizzard in South Dakota in the US.

But they did find that global warming doubled the chance of severe heat waves in Australia − making extreme summer temperatures five times more likely, increasing the chance of drought conditions sevenfold, and making hot temperatures in spring 30 times more probable.

And they reckoned that the record hot year of 2013 would have been virtually impossible without global warming. At a conservative calculation, the science showed that the heat of 2013 was made 2,000 times more likely by global warming.

Different picture

Paradoxically, Australia’s prime minister, Tony Abbott, was one of the world leaders who pointedly stayed away from the recent United Nations climate change summit in New York, and in the past has taken a sceptical stance on climate science. Yet research funded by Australian taxpayers has consistently painted a different picture.

“When it comes to what helped cause our hottest year on record, human-caused climate change is no longer a prime suspect − it is the guilty party,” said Dr Sophie Lewis, a paleoecologist at the Australian National University.

And her colleague, Sarah Perkins, a climate scientist at the Australian Research Council’s Centre of Excellence for Climate System Science, warned that 2013 was only the beginning.

She said: “If we continue to put carbon into our atmosphere at the currently accelerating rate, years like 2013 will quickly be considered normal, and the impacts of future extremes will be well beyond anything modern society has experienced.” – Climate News Network

Hungry invader fish stripping Mediterranean bare

Tropical rabbitfish have devastated algal forests in the eastern Mediterranean Sea Image: Zafer Kizilkaya
Tropical rabbitfish have devastated algal forests in the eastern Mediterranean Sea
Image: Zafer Kizilkaya

By Tim Radford

Warming seas are extending the range of tropical rabbitfish, whose voracious appetite for seaweed and other marine vegetation is turning areas of the Mediterranean Sea into rocky barrens.

LONDON, 3 October, 2014 − Scientists in Australia, Europe and the US have identified a new menace in the Mediterranean. The tropical rabbitfish has arrived in the eastern Mediterranean Sea and − wherever the waters are warm enough −  threatens to do to the marine vegetation what the terrestrial rabbit did to Australia’s tender grasses: eat the lot.

A team of researchers led by Adriana Vergés, a marine ecologist at the University of New South Wales in Sydney, Australia, and Fiona Tomas, assistant professor at the Mediterranean Institute for Advanced Studies in Mallorca, Spain, report in the Journal of Ecology that they surveyed 1,000 kilometres of coastline around Turkey and Greece.

Dominant species

They found that two species of rabbitfish have become dominant in the region, and they think the invader is likely to claim more territory as the world’s climate changes and the waters warm.

The range expansion of the rabbitfish, which first entered the Mediterranean basin from the Red Sea via the Suez Canal, provides a good example of how tropical herbivorous fish can impact on the structure of rocky bottoms in temperate seas.

“The study identified two clearly distinct areas −  warmer regions with abundant rabbitfish, and colder regions where they are rare or absent,” Dr Vergés said.

”The regions with abundant rabbitfish had become rocky barrens. There was a 65% reduction in large seaweeds, a 60% reduction in other algae and invertebrates, and a 40% reduction in the overall number of species present.”

The hungry herbivores were first reported in the eastern Mediterranean in 1927, and have recently been found off the coast of Croatia and even the south of France.

The invaders are a threat to ecosystems because seaweed forests − like terrestrial forests − provide food and shelter for hundreds of species.

Feeding behaviour

The researchers recorded fish feeding behaviour and noted that the rabbitfish were not noticeably more greedy than the natives. But whereas the native temperate herbivores grazed only on adult algae, the two species of rabbitfish consumed both the adult and the juvenile seaweeds. The consequence is that the full-grown species were not replaced.

In the long run, such seaweed clearance could be a threat not just to Mediterranean ecosystems but also to the Mediterranean diet, because these ecosystems ultimately support the shoals of sardines, anchovies, red mullet, sea bass, bream, tuna and other specialties of the tables of Spain, Greece and Italy.

“This research highlights the need to work out how the interactions between different species will change in a warming world,” Dr Vergés said. − Climate News Network

Warmer Atlantic widens invader’s hunting ground

Moving home: an Indo-Pacific lionfish on a reef off the North Carolina coast Image: NOAA
Moving home: an Indo-Pacific lionfish cruises on a reef off the North Carolina coast
Image: NOAA

By Tim Radford

The exotic lionfish, already a long way from the reefs of its Indo-Pacific home, is heading further north up the US coast as global warming causes big changes to ocean habitats.

LONDON, 28 September, 2014 − The venomous lionfish is on the move. This invasive species has been observed in deeper waters off the North Carolina coast since the turn of the century, but new research suggests it may now be expanding its range into the shallower levels.

Since the lionfish (Pterois volitans) is actually native to the Indo-Pacific region, it is already a long way from home. But what now gives it licence to hunt further north is warmer sea temperature.

Global warming has already begun to make huge differences to ocean habitat. The bluefin tuna is a temperate zone fish that has already been observed in Arctic waters off the coast of Greenland, and commercial species such as red mullet, a creature of the Mediterranean, has been seen in the North Sea and even in Norwegian waters.

Now researchers in the US have reported that the lionfish – an invader first observed off the Florida coast in the 1980s − is spreading through the north-west Atlantic.

Temperature is the key determinant for a fish on the move. Fisheries biologist Paula Whitfield, of the National Oceanic and Atmospheric Administration’s National Centres for Coastal Ocean Science, and colleagues report in the journal Marine Ecology Progress Series that they surveyed 40 species of fish off the reefs of North Carolina.

Tropical species

These reefs have always been home both to temperate and tropical species, at the limits of their ranges. But now the reefs are becoming more tropical − and so is the local population.

“Along the North Carolina coast, warming water temperatures may allow the expansion of tropical fish species, such as lionfish, into areas that were previously uninhabitable due to cold winter temperatures,” Whitfield says.

“The temperature thresholds collected in this study will allow us to detect and estimate fish community changes related to water temperature.”

The lionfish tends to prefer water warmer than 15.2°C, and so normally inhabits the warm currents of the deeper waters in the temperate Atlantic. It is a carnivore that seems to enjoy a wide range of prey. It makes itself at home in a wide variety of habitat, and is considered a serious threat to other species of reef fish. – Climate News Network

California burning points to more intense wildfires

Burning issue: a wildfire raging this month in California’s Yosemite National Park Image: PBJamesPhoto via Wikimedia Commons
Razed alarm: wildfire rages through part of California’s Yosemite National Park this month
Image: PBJamesPhoto via Wikimedia Commons

By Kieran Cooke

As the forest fires season peaks in the western US, a new report predicts that climate-led temperature rise will lead to millions more acres across the world being burned to the ground.

LONDON, 27 September, 2014 − Smoke from fires burning at present in northern California has been detected as far north as Canada, as thousands of firefighters battle to contain blazes that together cover nearly 300,000 acres of forest and shrub wood. And it looks like things are going to get worse.

A new report by the US-based Cost of Carbon Pollution project forecasts that such fires are going to become ever more intense in the years ahead – not just in the western US, but elsewhere round the world, and particularly in areas of southern Europe and in Australia.

The ongoing drought across much of the western US has had a serious impact on the region’s agricultural industry, and has resulted in the build-up of vast amounts of tinder-dry material on the land.

“We haven’t been out of fire season for a year and a half,” a leading fire official told the Washington Post. “There is no end in sight.”

Incidence doubles

The new report says the incidence of wildfires – unrestrained fires that burn predominantly in areas of forests, woodlands, grasslands, peat or shrubs – has doubled in the US since the 1990s.

In total, between seven and nine million acres in the US are burned as a result of wildfires every year – an area equivalent to one-and-a-half times the size of the state of Massachusetts.

“These amounts are expected to increase significantly due to climate change and other factors,” the report says. And, overall, there is likely to be a 50% increase by 2050 in the area of North America burned, with more large and potentially catastrophic wildfires.

Not only will more valuable forest be lost, the fires will also have an increasing impact on the economy − with important industries such as tourism suffering serious losses.

More and more people have been migrating to the western US. In 1960, California’s population was 15 million: it’s now nearly 40 million, and is expected to increase to 50 million by 2030. The study says the fires are already taking their toll on people’s health.

Forests and peat lands function as carbon sinks – sucking up volumes of greenhouse gases (GHGs). But the report says an increase in wildfires could mean that, in time, these areas would become net emitters of GHGs, adding to problems of global warming.

Mistaken policies

Dr Wallace Covington, director of the Ecological Restoration Institute at Northern Arizona University, is an internationally-recognised expert on forest restoration. He says that the growth in wildfires in the western US is due, to a large extent, to mistaken forest policies over the past 100 years.

Dense forests were planted, while natural fires – which form a normal part of nature’s cycle, and can regenerate growth in some trees and plants – were suppressed.

“Forests became unhealthy, and an excessive amount of fire fuel was allowed to build up,” Covington told the Climate News Network. “Natural fires can be easily controlled, but once fires spread over thousands of acres they are virtually impossible to contain.”

Covington says that climate change has exacerbated the situation. “We’re seeing wider swings from very dry to very wet conditions, and wind speeds, which fan the forest flames, have been building up across the region over recent years.”

Forest specialists at Northern Arizona University and elsewhere are now pressing for radical changes in forestry policy, including the thinning of densely-wooded areas and the reintroduction of controlled, natural fires at various times of the year. – Climate News Network