Climate change and extreme weather is likely to hit the Indian Ocean rim countries much harder over the coming century. That is the conclusion of a new study lead by CSIRO climate scientist Wenju Cai.
The research lead by Wenju Cai from CSIRO's Marine and Atmosphere Division outlines that an increase in greenhouse gases and climate change is likely to cause more extreme positive Indian Ocean Dipole (IOD) events to occur and that this will likely triple the frequency of bushfires, floods and drought in Australia, Africa and India from one event every 17 years to one every 6 years.
The interaction between ENSO and IOD still needs much more research and study to understand. IOD events are often triggered by El Nino, but can also sometimes occur during La Nina years as well.
"Most of our severe bushfires were preconditioned by the Indian Ocean Dipole... When a summer season is preceded by an [extreme positive] Indian Ocean Dipole our bushfires tend to be much more severe.
"Now this is in Australia, but it has global impact. [For example] in Indonesia, a positive Indian Ocean Dipole tends to cause drought. You may recall in 1997 we had a wild bushfire in Indonesia... emitting a lot of pollutants and smoke that caused health problems to many millions of people in the region and also cost lost economic activity because people couldn't go out because of the visibility problem.
"In the meantime, in eastern African countries, they experienced devastating floods, causing thousands to die... and displacement of many hundreds of thousands."
The speeding up and movement south of the Westerlies is bad news for farmers reliant on winter rainfall over the southern part of Australia. It comes at a time when the Murray Darling Basin is still under stress with the Abbott Government announcing the closure of the National Water Commission, which advises the Australian Government on progress on water policy issues and the accountability of State and Federal Government in this area. The closure will save $19.5 million over the next four years.
One needs to ask how much this closure may cost the Australian economy in reduced agricultural productivity through poor water management through the next period of extensive drought conditions.
“Taking the eye off water is foolhardy,” Mike Young, Gough Whitlam and Malcolm Fraser Chair in Australian Studies at Harvard University, said in e-mail to Circle of Blue. “National oversight of water is critical to the future of Australia.”
The Southern Annular Mode consists of Westerly winds that blow continuously over the southern ocean, helping to insulate the southern continent of Antarctica. In recent decades these winds have sped up and moved further south as a result of climate change. This results in drawing rain clouds to the south away from Australia particularly affecting Autumn and winter rainfall.
The Bureau of Meteorology has observed a long term trend for south-eastern and south western Australia becoming more dry. New research has identified reasons for this and why Antarctica has not experienced a warming trend like the rest of the planet.
Western Australia has suffered a 20 per cent loss in winter rainfall since the 1960s. South eastern Australia has suffered a 10 per cent reduction in winter rainfall from the 1990s.
While politicians have effectively dithered on robust action to reduce greenhouse gas emissions over the last 20 years we are hearing more about geo-engineering proposals to moderate rising temperatures. But the latest study from the University of Reading scientists modelling solar radiation management, and in particular atmospheric aerosol injection - one of the easiest geo-engineering proposals to do at large scale - says such a project would result in a major decrease in tropical rainfall and an increase in drought in many regional areas.
The Reading University study concentrated on the consequences on geo-engineering methods to change the solar radiation reaching the earth: through mirrors above the atmosphere; and injecting sulfate aerosols into the atmosphere to reflect solar radiation. The first could prove hideously expensive and is at the moment impractical, but the second method is quite achieveable at reasonable cost.
The study - Weakened tropical circulation and reduced precipitation in response to geoengineering (Full paper) - looks at aerosol injection in particular and the projected impacts. It was published in Environmental Research Letters.
Scientists from the UK's Met Office have researched the causes of the 2011 East African drought and found human caused climate change was a significant contribution. The drought was a humanitarian disaster that killed an estimated 50,000 people, with 13 million in need of assistance in Somalia, Djibouti, Ethiopia and Kenya. Almost 30,000 children under the age of five were believed to have died of malnutrition in Somalia.
The drought had two components - the 'short rains' of October - November rainy season in 2010 which failed to appear, and then the absence of the 'long rains' from March - June of 2011 which really created the humanitarian crisis. The UN declared a famine on 20 July in southern Somalia, the first famine declared globally in 30 years. It was categorised as the worst drought in the region for 60 years.
Climate scientist Simon Mason from Columbia University said that East Africa has experienced a strong drying trend over the last 10 years. It is thought that rising sea surface temperatures in the Indian Ocean create conditions that pull moisture away from East Africa.
Taking action on Climate Change is looming for President Obama. The United States experienced it's warmest year on record in 2012 according to NOAA. 2012 was also the second most extreme year on record. Over 70 environment organisations have urged Obama to use the Clean Air Act to reduce greenhouse gas emissions and provide clean energy jobs.
The contigous United States had an average annual temperature of 55.3°F which was 3.2°F above the 20th century average. The 2012 annual temperature was 1.0°F warmer than the previous record warm year of 1998. Read a quick summary by the World Resources Institute: By the Numbers: The Hottest Year on Record
"In 117 years of data the record low temperatures to 1998's previous record high average, all sit within a four degree Fahrenheit band, 2012 is 1 degree Fahrenheit above that band," said Jake Crouch, climate scientist, NOAA's National Climatic Data Center (NCDC).
The extent of heat records broken in 2012 is a disturbing trend globally. Australia is currently experiencing an extreme heatwave with Australia's Bureau of Meteorology saying that many temperature records exceeded and requiring an extra two colours added to the top end of the temperature scale.
Shaye Wolf, climate science director with the Center for Biological Diversity made a brief statement in reaction to the NOAA announcement calling for President Obama to use his powers through the Clean Air Act to fight greenhouse gas emissions.
"This disturbing news puts the heat on President Obama to take immediate action against carbon pollution," said Dr. Wolf. "The blazing temperatures that scorched America in 2012 are a bitter taste of the climate chaos ahead. Science tells us that our rapidly warming planet will endure more heat waves, droughts and extreme weather. The president needs to start making full use of the Clean Air Act to fight greenhouse gas emissions, before it's too late."
The widespread and persistent drought in the US during 2011-2012 has expanded according to the US Drought Monitor as reported on Climate Central. Are we starting to see the signs of a megadrought in the US southwest? Are human influences such as climate change contributing to or causing this widespread extreme weather event?
As of 18 September 2012, 64.82 percent of the contiguous U.S. has been declared as suffering from at least moderate drought - a new record. Extreme drought occurs across 20.74 percent, while the most severe category has ravaged 6.26 per cent of the land. And the seasonal outlook provided by NOAA provides little happy news predicting the drought will persist till the end of the year.
The drought is the worst to occurr since the dustbowl years of the 1930s and comes as North America experiences well above normal temperatures over spring and summer breaking many temperature records with the first half of 2012 being the hottest on record for the United States. July 2012 was the hottest month on record for the continental United States. But Australia and a few other places had abnormally cool month so putting the chill on a hot July for a global record.
A new international scientific study lead by a researcher from the University of Utah links extreme fire weather to increasing temperatures and drought driven by climate change.
The study, lead by geography professor Mitchell Power, found that the extent and intensity of wildfires on a continental and global basis is connected to changing temperatures and climate. The study dismissed the theory that population decline was the primary cause for reduced wildfire during the cooler periods in the last 2000 years arguing "climate change was likely more important than indigenous population collapse in driving this decline."
Back-to-back La Niña events has produced the wettest two year period on record for Australia according to the Bureau of Meteorology (BOM). The two year rainfall total for 2010-2011 of 1409 mm, eclipsed the old record of 1407 mm set during the big wet of 1973-1974. But underlying this wet record is a strong drying trend in the southeast and southwest of the continent with a consistent reduction in Autumn and winter rainfall and streamflow which are important for both agriculture and water storage.
Climate change induced drought and water stress is increasing tree mortality in Canada's boreal forests, particularly in western Canada, resulting in a reduction in biomass which reduces it's capacity as a carbon sink. As tree mortality increases, there is reduced capacity to absorb carbon dioxide, resulting in a feedback loop where conditions become warmer and drier increasing the stress on the boreal forest ecosystem and ability to absorb carbon dioxide that humans keep on pumping into the atmosphere at increasing rates.
Over the weekend the Intergovernmental Panel on Climate Change (IPCC) released the Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). There were no surprises for anyone who follows climate science, and the report succinctly integrates a discussion of vulnerability, risk management and adaptation strategies for extreme weather disasters.
The report looks at the evidence for each extreme weather event and gives an assessment of probability and confidence value of each weather event assessment and the future trend. It involved some 220 expert authors from 62 countries and involved more than 18,000 review comments.
A new study by NOAA - the US National Oceanic and Atmospheric Administration - has highlighted that climate change is a major contributor to more frequent Mediterranean droughts. According to the study in the last 20 years, 10 of the driest 12 winters have taken place in the lands surrounding the Mediterranean Sea. Water security, food security, and increasing wildfire frequency and intensity has the potential to destabilize the region producing conflicts over use of increasingly scarce water resources.
"The magnitude and frequency of the drying that has occurred is too great to be explained by natural variability alone,” said Martin Hoerling, Ph.D. of NOAA’s Earth System Research Laboratory in Boulder, Colorado, lead author of a paper published online in the Journal of Climate this month. “This is not encouraging news for a region that already experiences water stress, because it implies natural variability alone is unlikely to return the region’s climate to normal.”
An extreme shift in weather in June across much of southern and eastern China has been put down to the effects of global warming and climate change. Usually light rains start in June in the middle and lower Yangtze valley leading in to the summer monsoonal rains and typhoon season, but this year torrential rains and storms struck on June 3 and have continued unleashing devastating floods, the worst in over 50 years.
Chen Zhenghong, senior engineer at the Meteorological Bureau of Central China's Hubei province, said the sharp shift between drought and flood in East and Central China was a result of global warming, according to a Xinhua News Agency report in China Daily on 17 June.
While flood waters continue to rage in Queensland with more rain continuing to fall, debate on the Murray Darling Basin is stepping up. Flood waters are slowly making there way down the Murray Darling system to the Lower Lakes of the Coorong.
The Murray Darling Basin has experienced its wettest year on record and there are now calls for the basin water plan to be deferred and for dams to be built to mitigate future flooding. The Australian Conservation Foundation argues strongly the water basin needs to be reformed now.
“Basin communities depend on a healthy Murray-Darling. The Basin Plan must not be delayed, stymied and used as a political football or the Murray-Darling and its communities will lose out and continue facing uncertainty. The Murray-Darling needs a solution, not more delay and inaction.” said Ruchira Talukdar, ACF Healthy Ecosystems campaigner. in a media release.
With the release of the CSIRO report on Climate variability and change in south-eastern Australia (CSIRO: South East Australia becoming drier, Global Warming implicated) CSIRO hydrologist and lead author Dr David Post has come under criticism for comments on whether anthropogenic global warming has contributed to drought conditions in south east Australia.
Dr David Post said in a CSIRO media release on October 22 that "The research indicates that these changes can be linked to global warming, making it a likely contributor to the recent drought."
In January 2010 David Post released a report on the potential climate impacts regarding Water Yield availability in Tasmania. He was interviewed in regard to this report in the Canberra Times and was attributed with saying there was "no evidence" linking drought to climate change in eastern Australia: "At this stage, we'd prefer to say we're talking about natural variability. The science is not sufficiently advanced to say it's climate change, one way or the other. The jury is still out on that," (Canberra Times, Jan 19, 2010 - Jury still out on climate change: CSIRO.
Caption: Figure 1. Rainfall deciles across Australia for 1 January 1997 to 31 December 2009; deciles based on climatology from 1900 to 2009 (Bureau of Meteorology) - from the report
A new report into the changing climate of South East Australia and particularly the Murray Darling Basin indicates an increasing risk of below average rainfall and runoff into streams and generally drier conditions. The change in the climate has, at least in part, been attributed to an increase in atmospheric anthropogenic greenhouse gases associated with global warming.
The South Eastern Australian Climate Initiative (SEACI) report: Climate variability and change in south-eastern Australia, highlights the effects of climate variability and change on the water resources of the south-east which should have major implications for water allocations planning currently under consideration by the Murray Darling Basin Authority and in community hearings. The research was undertaken by the CSIRO and Bureau of Meteorology.
Extreme Drought and aridity is likely to increase within decades across much of Africa, Australia, North and South America, South west Asia, and around the Mediterranean Sea according to a new study by National Center for Atmospheric Research (NCAR) scientist Aiguo Dai.
Dai used 22 computer climate models and a comprehensive index of drought conditions, as well as analyses of previously published studies for his review. Extreme drought may reach such a scale in some regions by the end of the century that has rarely, if ever, been observed in modern times.
2009 is likely to be the fifth warmest year on record according to the World Meteorological Organisation, with the current decade being the warmest on record, eclipsing the 1990s, which in turn was warmer than the 1980s.
Above normal temperatures were recorded for most regions with North America experiencing conditions colder than normal in some regions. Global warming is producing more weather extremes, at greater frequency and intensity.
With the hacking of emails from the University of East Anglia there have been calls by climate deniers and some commentators like George Monbiot for scientific data to be made more public. In response, the UK Met Office has released station temperature records for over 1,500 of the stations that make up the global land surface temperature record. More data will be made available in the future and placed in the public domain for scrutiny.
The Temperature is Rising
The global combined sea surface and land surface air temperature for 2009 (up to October) was estimated at 0.44°C ± 0.11°C (0.79°F ± 0.20°F) above the 1961-1990 annual average of 14.00°C/57.2°F.
As the atmosphere and oceans warm up, more water vapour can be carried, storms will be more intense and more frequent. We will experience more extreme weather events. We are seeing more extreme weather events, with many precipitation and temperature records are being broken.
The year was the third warmest in China since 1951 and for some regions 2009 was the warmest year. A heatwave in July broke some local temperature records.
In Europe spring was very warm with temperatures 5 degrees above average during April in central Europe breaking several records. The European summer was also warmer than the long-term average. Spain recorded the third-warmest summer, and Italy suffered a strong heatwave in July with temperatures soaring over 40°C, and reaching 45°C at some locations. The July heatwave also affected the United Kingdom, France, Belgium , Germany, and Scandanavian countries setting new maximum records.
The year was marked by climate extremes with devastating floods, severe droughts, snowstorms, heatwaves and cold waves, recorded around the world.
Canada and Alaska experienced a hot July with Vancouver and Victoria setting new temperature records and Alaska recording the second warmest July on record. However, October proved to be the third-coolest October on record for the United States.
In the Southern Hemisphere autumn proved to be exceedingly warm across Argentina, Uruguay, Paraguay and southern Brazil with several temperature records broken.
China is in its worst drought in 50 years. One the weakest monsoon seasons for India caused severe drought in many districts. Severe drought continues in East Africa decimating crop harvests and livestock, leading to food shortages. Exceptional drought was also recorded during October in Mexico, the US Southwest, and Argentina. The Murray Darling Basin, Australia's food bowl, is in its 9th year of drought. The South west corner of Western Australia and South eastern Australia continues to receive below average rainfall.
The WMO has also warned that the frequency and severity of droughts are likely to increase. The Australian Bureau of Meteorology has noted that: "The combination of record heat and widespread drought during the past five to ten years over large parts of southern and eastern Australia is without historical precedent and is, at least partly, a result of climate change."
While the Copenhagen COP15 talks are underway, meteorologists, climatologists and other researchers are meeting at the University of Nebraska from 8 to 11 December 2009 at the 'Inter-Regional Workshop on Indices and Early Warning Systems for Drought'.
"There is a critical need to establish best practices for drought early warning systems throughout the world. This requires that we develop a better understanding of the tools and data sources that are important components of these systems. Drought is a serious problem in virtually all countries. Projected changes in climate for many regions suggest that droughts are likely to become more frequent, of longer duration, and more severe. Our ability to lessen or mitigate the impacts associated with drought is contingent on putting in place comprehensive early warning systems.", said Dr Don Wilhite, Director and Professor, School of Natural Resources of the University of Nebraska, at the opening of the workshop.
Storms
Intense storms affected Spain and France in January; severe damage by a winter storm in western Europe resulting in serious disruptions to air and rail traffic across the region. Thunderstorms and extreme rainfall events across Europe and Turkey, culminating in a record rainfall in 24 hours for Great Britain in November resulting in flooding and damage to bridges.
In South America heavy rainfall occurred in Colombia at the start of the year, producing landslides and widespread floods. Later, North-east Brazil experienced heavy rainfall and flooding, and in Winter the worst snowstorm for 15 years hit the southern part of Argentina. Intense rainfall breaking monthly precipitation records and flooding ocurred in north-eastern Argentina, southern Brazil and Uruguay in November.
A record number of tornadoes were witnessed in Ontario, Canada, and Canadian avalanches were almost double the yearly average for the past decade. The United States experienced its wettest October in 115 years, with record flooding during March in the northern plains region.
192 people died in El Salvador when an intense storm associated with Hurricane Ida, produced deadly floods and landslides.
Southern India experienced incessant rain resulting in severe flooding during September and October.
A severe snowstorm in Northern China in early November, one month earlier than normal, broke local weather records.
Torrential rain and flooding ocurred in Western Africa, Zambia and Namibia. Burkina Faso experienced 263 mm of rain recorded in less than 12 hours, breaking a record set 90 years ago. Flooding affected over 100,000 people in West Africa and a further 1 million people in southern Africa.
While extreme heatwave and bushfires hit south eastern Australia in February, at the same time large parts of Queensland and coastal New South Wales were subject to torrential rain and flooding. In September and October eastern Australia was affected by dust storms carrying dust from central Australia, reducing visibility.
Arctic Sea Ice
The Arctic experienced its third lowest sea ice extent over the Northern summer, with only 2007 and 2008 being lower.
More importantly, sea ice thickness is also in rapid decline, with much of the purported multi-year ice as detected by microwaves from satellite proven by new research to be 'rotten' ice unexpectedly thin that electromagnetically fools the satellite measurement instruments. The Research was conducted by Dr David Barber, a professor of Environment and Geography and Canada Research Chair in Arctic System Science from the University of Manitoba.
"Our results are consistent with ice age estimates that show the amount of multiyear sea ice in the northern hemisphere was the lowest on record in 2009 suggesting that multiyear sea ice continues to diminish rapidly in the Canada Basin even though 2009 aerial extent increased over that of 2007 and 2009," Dr David Barber concludes in his paper which has been accepted for publication in Geophysical Research Letters.
This latest research was conducted In September 2009 by Barber and others in the southern Beaufort Sea aboard the research vessel (NGCC) Amundsen. Much of the ice encountered, sometimes 6-8 metres thick, was so heavily decayed the Amundsen easily broke through the floes. For much of the journey the ship sailed at close to its open water cruising speed of about 25km/h.
"This has significant implications for assessment of the speed of global climate change impacts in the Arctic and for increased shipping and industrial development in the Arctic," said Barber.
Image Label: This depiction of linear trends in the Palmer Drought Severity Index from 1948 to 2002 shows drying (reds and pinks) across much of Canada, Europe, Asia, and Africa and moistening (green) across parts of the United States, Argentina, Scandinavia, and western Australia. (Illustration courtesy Aiguo Dai and the American Meteorological Society.)
According to a new analysis by scientists at the National Center for Atmospheric Research (NCAR) in the USA the percentage of Earth's land area stricken by serious drought more than doubled from the 1970s to the early 2000s. Iguo Dai, lead author of the study, said that rising global temperatures appear to be a major factor. Widespread drying occurred over much of Europe and Asia, Canada, western and southern Africa, and eastern Australia.
