Water supply of 2 billion people undermined by future global warming
by Philippus Wester
International Centre for Integrated Mountain Development, agencies
Feb. 2019 (ICIMOD, news agencies)
At least a third of the ice fields in Asia’s towering mountain chain are predicted to melt due to climate change, according to a landmark report, with serious consequences for almost 2 billion people.
Even if carbon emissions are dramatically and rapidly cut and succeed in limiting global warming to 1.5C, 36% of the glaciers along in the Hindu Kush and Himalaya range will have gone by 2100. If emissions are not cut, the loss soars to two-thirds, the report found.
The glaciers are a critical water store for the 250 million people who live in the Hindu Kush-Himalaya (HKH) region, and 1.65 billion people rely on the great rivers that flow from the peaks into India, Pakistan, China and other nations.
“This is the climate crisis you haven’t heard of,” said Philippus Wester of the International Centre for Integrated Mountain Development (Icimod), who led the report. “In the best of possible worlds, if we get really ambitious [in tackling climate change], even then we will lose one-third of the glaciers and be in trouble. That for us was the shocking finding.”
Wester said that, despite being far more populous, the HKH region had received less attention than other places, such as low-lying island states and the Arctic, that are also highly vulnerable to global warming.
The new report, requested by the eight nations the mountains span, is intended to change that.
More than 200 scientists worked on the report over five years, with another 125 experts peer reviewing their work. Until recently the impact of climate change on the ice in the HKH region was uncertain, said Wester. “But we really do know enough now to take action, and action is urgently needed,” he added.
The region runs from Afghanistan to Myanmar and is the planet’s “third pole”, harbouring more ice than anywhere outside Arctic and Antarctica.
Limiting the global temperature rise to 1.5C above pre-industrial levels requires cutting emissions to zero by 2050. This is considered to be optimistic by many, but still sees a third of the ice lost, according to the report. If the global rise is 2C, half of the glaciers are projected to melt away by 2100.
Since the 1970s, about 15% of the ice in the region has disappeared as temperatures have risen. But the HKH range is 3,500km long and the impact of warming is variable. Some glaciers in Afghanistan and Pakistan are considered more stable, most probably due to increased cloud cover that shields the sun and changed winds that bring more snow. But even these will start melting with future warming, Wester said.
The melting glaciers will increase river flows through to 2050 to 2060, he said, pushing up the risk of high-altitude lakes bursting their banks and engulfing communities. But from the 2060s, river flows will go into decline. The Indus and central Asian rivers will be most affected. “Those areas will be hard hit,” said Wester.
Lower flows will cut the power from the hydrodams that generate much of the region’s electricity. But the most serious impact will be on farmers in the foothills and downstream. They rely on predictable water supplies to grow the crops that feed the nations in the mountains’ shadows.
But the changes to spring melting already appear to be causing the pre-monsoon river flow to fall just when farmers are planting their crops. Worse, said Wester, the monsoon is also becoming more erratic and prone to extreme downpours. “One-in-100 year floods are starting to happen every 50 years,” he said.
The new report highlights how vulnerable many mountain people are, with one-third living on less than $1.90 a day and far away from help if climate disaster strikes.
Political tensions between nations could add to the difficulties. “There are rocky times ahead for the region. Because many of the disasters and sudden changes will play out across country borders, conflict among the region’s countries could easily flare up,” said Eklabya Sharma, the deputy director general of Icimod.
Hamish Pritchard, a glaciologist at the British Antarctic Survey and not part of the report, said it is “a substantial piece of work” that takes due note of the uncertainties resulting from the limited snowfall and ice measurements in the high mountains.
He said glaciers currently provide an essential buffering role as their meltwater flows into the rivers during the summer, which is when water is in greatest demand downstream and periodic droughts have the deadliest impacts on populations. “Take the ice away and those people are exposed to serious water stress and the consequences of that are local, regional and potentially global, in terms of conflict and migration,” he said.
* Access the report: http://bit.ly/2WJKs6b
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Heatwaves are becoming more intense, extended and frequent as a result of climate change
by World Meteorological Organization (WMO)
6 Feb. 2019
World Meteorological Organization confirms past 4 years were warmest on record
In a clear sign of continuing long-term climate change associated with record atmospheric concentrations of greenhouse gases, 2015, 2016, 2017 and 2018 have been confirmed as the four warmest years on record.
A consolidated analysis by the World Meteorological Organization of five leading international datasets showed that the global average surface temperature in 2018 was approximately 1.0° Celsius (with a margin of error of ±0.13°C) above the pre-industrial baseline (1850-1900). It ranks as the fourth warmest year on record.
The year 2016, which was influenced by a strong El-Niño event, remains the warmest year on record (1.2°C above preindustrial baseline). Global average temperatures in 2017 and 2015 were both 1.1°C above pre-industrial levels.
The latter two years are virtually indistinguishable because the difference is less than one hundredth of a degree, which is less than the statistical margin of error.
“The long-term temperature trend is far more important than the ranking of individual years, and that trend is an upward one, “ said WMO Secretary-General Petteri Taalas. “The 20 warmest years on record have been in the past 22 years. The degree of warming during the past four years has been exceptional, both on land and in the ocean.”
“Temperatures are only part of the story. Extreme and high impact weather affected many countries and millions of people, with devastating repercussions for economies and ecosystems in 2018,” he said.
“Many of the extreme weather events are consistent with what we expect from a changing climate. This is a reality we need to face up to. Greenhouse gas emission reduction and climate adaptation measures should be a top global priority,” said Mr Taalas.
The month of January has been marked by high impact weather in many parts of the world, including dangerous and extreme cold in North America, record heat and wildfires in Australia, high temperatures and rainfall in parts of South America, and heavy snowfall in the Alps and Himalayas.
Large parts of North America have been gripped by an influx of Arctic air. Combined with gusty winds, this is producing dangerous wind chills across a significant portion of the Upper Midwest into the Northeast USA. The frigid airmass is also supporting heavy lake effect snows downwind of the Great Lakes. The US National Weather Service said that temperatures will be well below average over the Upper Mississippi Valley, Great Lakes, into parts of the Northern Mid-Atlantic. In southern Minnesota, the wind chill factor pushed readings down to minus 65°F (-53.9°C) on 30 January. The national low temperature record was measured at minus 56 °F (-48.9°C).
The bitterly cold temperatures are caused by the influence of the Polar Vortex. This is a large area of low pressure and cold air surrounding the North Pole, with strong counter-clockwise winds known as the jet stream that trap the cold around the Pole. Disturbances in the jet stream and the intrusion of warmer mid-latitude air masses can alter the structure and the dynamics of the Polar Vortex, sending Arctic air south into middle latitudes and bringing warmer air into the Arctic. This is not a new phenomenon, although there is increasing research into how it is being impacted by climate change.
“The cold weather in the eastern United States certainly does not disprove climate change,” said WMO Secretary-General Petteri Taalas.
“In general, and at global level, there has been a decline in new cold temperature records as a result of global warming. But frigid temperatures and snow will continue to be part of our typical weather patterns in the northern hemisphere winter. We need to distinguish between short-term daily weather and long-term climate,“ he said.
“Arctic has faced warming, which is twice the global average. A large fraction of the snow and ice in the region has melted. Those changes are affecting weather patterns outside the Arctic in the Northern Hemisphere. A part of the cold anomalies at lower latitudes could be linked to the dramatic changes in the Arctic. What happens at the poles does not stay at the poles but influences weather and climate conditions in lower latitudes where hundreds of millions of people live,” he said.
The eastern USA and parts of Canada are seeing record-breaking cold temperatures, but Alaska and large parts of the Arctic have been warmer than average.
In Canada, Ottawa airport received a record 97 cm of snow on 29 January, beating the 1999 record of 93 cm, according to Environment and Climate Change Canada.
Winter snowstorms and heavy snowfall are also not inconsistent with weather patterns under a changing climate.
Parts of the European Alps saw record snowfalls earlier in January. In Hochfilzen in the Tirol region of Austria, more than 451 centimetres (cm) of snow fell in the first 15 days of January, an event statistically only expected once a century. Other resorts in Tirol also received once-in-a-century snowfalls. Eastern Switzerland received twice as much snow as the long-term average.
The German weather service or Deutscher Wetterdienst, DWD, also issued a number of top-level snow and winter weather warnings. Climate projections show that winter precipitation in Germany is expected to be more intense, according to the German Weather Service, DWD. This will necessitate adaptation measures, for instance in regulations for buildings to withstand the weight of snow.
During the month, severe winter storms have hit the eastern Mediterranean and parts of the Middle East, with particularly severe impacts on vulnerable populations including refugees.
A cold front in the third week of January that swept south through the Arabian Peninsula, bringing a widespread dust storm from Egypt to Saudi Arabia, Bahrain, Qatar, Iran and the United Arab Emirates, brought heavy rain and precipitation to Pakistan and northwest India.
The Indian Meteorological Department issued warnings on 21 January of heavy or very heavy rain and snow for Jammu and Kashmir and Himachal Pradesh, prompting warnings of avalanches amid an intense cold wave.
Australian heatwave and fires
Australia had its warmest January on record, according to its Bureau of Meteorology. The month saw a new series of heatwaves unprecedented in their scale and duration. Overall rainfall was 38% below average for January. Tasmania had its driest January on record.
Australia saw an unusual extended period of heatwaves which began in early December 2018 and continued into January 2019. The city of Adelaide reached a new record 46.6C on 24 January. Other records in South Australia included Whyalla 48.5, Caduna 48.6°C, Port Augusta 49.1°C, according to the Bureau of Meteorology.
Large fires fuelled by extremely dry and hot conditions have been burning since mid-January in central and southeast Tasmania, the southernmost state of Australia. As of January 28, the Tasmania Fire Service reported 44 fires.
News outlets reported smoke from some of the fires was visible as far away as New Zealand, and had a serious impact on air quality. The Tasmania Fire Service issued several emergency warnings to residents to relocate, as dangerous fire conditions and strong wind persist.
Many of the fires are in the world heritage area, hitting rare gondwana ecosystems only found in Tasmania which historically do not burn.
Over the past several weeks, the sea surface temperatures (SSTs) have warmed in the Tasman Sea with anomalies of +2.0˚C to 4.0˚C. Compared to the exceptional conditions at this time last year, SSTs are even warmer to the north and east of New Zealand and about equally as warm in the Tasman Sea, according to the New Zealand Institute of Water and Atmospheric Research.
Given that SSTs have been significantly warmer than average for several weeks, marine heatwave conditions are likely now occurring in parts of the Tasman Sea and New Zealand coastal waters, it said.
Australia had its hottest month of December on record and its hottest December day (27 December) on record. Marble Bar, in Western Australia, recorded a temperature of 49.3 °C on 27 December.
This followed an extreme heatwave that affected the tropical Queensland coast during late November 2018. Temperatures spiked again in mid-January, topping 45°C in many places in New South Wales and central Australia on 16 January.
Australia''s annual mean temperature has warmed by just over 1 °C since 1910, and summer has warmed by a similar amount. Australia''s annual warming trend is consistent with that observed for the globe, according to the Bureau of Meteorology.
Heatwaves are becoming more intense, extended and frequent as a result of climate change and this trend is expected to continue.
Elsewhere in the southern hemisphere, heat records tumbled in Chile. A weather station in the capital Santiago set a new record of 38.3°C on 26 January. In other parts of central Chile, temperatures topped 40°C, according to Meteo Chile.
Argentina has also been gripped by a heatwave, prompting a number of alerts about high temperatures.. Northeast Argentina, and the adjacent parts of Paraguay, Uruguay and Brazil have been hit with extensive flooding, with well above the long-term expected average rainfall.
On January 8, the Argentine city of Resistencia recorded 224mm rainfall. This is a new 24-hour rainfall record, much higher than the previous highest of 206mm, recorded in January 1994, according to the national meteorological service, SMN Argentina.
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