World’s major cities to face ‘unknown’ climate conditions by 2050

World’s major cities to face ‘unknown’ climate conditions by 2050

SOURCE: Reuters and PLOS One DATE: July 10, 2019 SNIP: A fifth of the world’s major cities will face “unknown” climate conditions by 2050, researchers warned on Wednesday, as rising temperatures heighten the risks of drought and flooding. Climate scientists at the Crowther Lab, a research group based at ETH Zurich, a science and technology university, analyzes 520 cities across the world, including all capitals and most urban centers with a population of more than 1 million. Looking at current climate conditions in these cities – including precipitation and seasonal data – scientists projected what would happen as temperatures rise another half degree, to near the lower 1.5 degree Celsius target set in the 2015 Paris Agreement on climate change. It showed that 22% of the cities will experience unprecedented climate conditions by 2050, such as more intense dry and monsoon seasons, said Jean Francis-Bastin, the lead author of the report. Crowther Lab scientists said their study, published in the journal PLOS ONE, was the first global analysis of the likely shifts in climate conditions in major cities as a result of global warming. It showed that 77% of the cities it looked at will experience a striking change in climate conditions by 2050. Across the northern hemisphere, many cities in 30 years time could resemble places that are over 1,000 km (620 miles) further south toward the equator, said the study, which projected conditions if current plans to cut climate-changing emissions go ahead. Of the 22% of cities that will see ‘unprecedented’ climate shifts, 64% are located in the tropics and include Kuala Lumpur, Jakarta, Rangoon and Singapore,...
Anchorage hits an official 90 degrees for the first time on record

Anchorage hits an official 90 degrees for the first time on record

SOURCE: Anchorage Daily News DATE: July 5, 2019 SNIP: The National Weather Service said Friday it took a long look at Thursday’s record afternoon temperatures before announcing late in the day that the thermometer had reached an astonishing 90 degrees at the official recording site at Ted Stevens Anchorage International Airport. The weather service first reported that a record of 89 degrees had been reached in an hourly sampling of airport weather. The actual temperature was 89.1, but it is the weather service’s practice to round to the nearest whole number. But because the temperature of record is collected at an airport, it is sampled more frequently than on the hour, an NWS official in Anchorage said. Upon evaluation of minute-to-minute temperatures, the weather service said, meteorologists saw that at exactly 5 p.m. the temperature spiked to 89.6 degrees before cooling back down to 87.8 five minutes later. Anchorage’s new highest temperature on record — after rounding – is now 90 degrees on Independence Day, 2019. The previous record of 85 was set on June 14, 1969. The average high for July 4 in Anchorage is...
More than half the world could see ‘record-setting heat’ every year by 2100

More than half the world could see ‘record-setting heat’ every year by 2100

SOURCE: Carbon Brief DATE: June 17, 2019 SNIP: More than half of the world could see new temperature records set in every single year by the end of the century if global warming is not curbed, a study finds. And new heat records could be set in two-thirds of the world’s least developed countries each year by 2100 under the same scenario, the research adds. Limiting global warming to below 2C above pre-industrial levels could reduce the extent of land seeing record-setting heat by almost three quarters, the lead author tells Carbon Brief. The new study, published in Nature Climate Change, explores how often new temperature records are likely to be set in the future across every world region. The authors used climate models to explore how often new temperature records are likely to be set – and “smashed” – across the globe. They investigated record-setting heat under two possible future scenarios: one with very high greenhouse gas emissions (“RCP8.5”) and one where global warming is limited to below 2C (“RCP2.6”). The results show that, under the high-emissions scenario, up to 58% of the world could see a new temperature record set in at least one month every year by 2100. If temperature rise is limited to 2C, a smaller 14% of the world would see new record temperatures every year by that time. One limitation is that climate models are generally better at projecting future temperature averages than future temperature extremes – which are outliers in the...
Record-Breaking Heat in Alaska Wreaks Havoc on Communities and Ecosystems

Record-Breaking Heat in Alaska Wreaks Havoc on Communities and Ecosystems

SOURCE: Smithsonian Magazine DATE: May 30, 2019 SNIP: Alaska in March is supposed to be cold. Along the north and west coasts, the ocean should be frozen farther than the eye can see. In the state’s interior, rivers should be locked in ice so thick that they double as roads for snowmobiles and trucks. And where I live, near Anchorage in south-central Alaska, the snowpack should be deep enough to support skiing for weeks to come. But this year, a record-breaking heatwave upended norms and had us basking in comfortable—but often unsettling—warmth. Across Alaska, March temperatures averaged 11 degrees Celsius above normal. The deviation was most extreme in the Arctic where, on March 30, thermometers rose almost 22 degrees Celsius above normal—to 3 degrees. That still sounds cold, but it was comparatively hot. The state’s wave of warmth was part of a weeks-long weather pattern that shattered temperature records across our immense state, contributing to losses of both property and life. On April 15, three people, including an 11-year-old girl, died after their snowmobiles plunged through thin ice on the Noatak River in far northwestern Alaska. Earlier in the winter, 700 kilometers south, on the lower Kuskokwim River, at least five people perished in separate incidents when their snowmobiles or four-wheelers broke through thin ice. There were close calls too, including the rescue of three miners who spent hours hopping between disintegrating ice floes in the Bering Sea near Nome. Farther south, people skating on the popular Portage Lake near Anchorage also fell through thin ice. Varying factors contributed to these and other mishaps, but abnormally thin ice was...
The heat is on: Amazon tree loss could bring 1.45 degree C local rise

The heat is on: Amazon tree loss could bring 1.45 degree C local rise

SOURCE: MongaBay DATE: May 14, 2019 SNIP: It is well known that the burning of fossil fuels and deforestation both lead to the emission of carbon dioxide, raising temperatures worldwide. Less well understood is how removing tree cover is contributing to increased temperatures at a local level – until now. In a new study published in the open-access journal PLOS ONE, scientists from Brazil’s Rio de Janeiro State University and the University of California, Santa Cruz (UCSC), have found that the temperature increase in the immediate vicinity of a deforested area could be as much as 1.45 degrees Celsius (2.6 degrees Fahrenheit) by 2050 in tropical areas such as Brazil’s Amazon basin or in the Cerrado, the nation’s savanna biome. “Everyone is familiar with how hot it is in cities compared to a forest environment, and this is because the energy is absorbed and then generates infrared radiation that heats up the environment. The same happens if you deforest,” explained study co-author Barry Sinervo of the UCSC Department of Ecology and Evolutionary Biology in a Mongabay interview. The paper explores how the albedo effect (whereby lighter-colored surfaces reflect heat, while darker ones absorb it), and the loss of evapotranspiration (whereby water goes back into the atmosphere from land, trees and plants) can both lead to warming on a local scale within deforested tropical areas. By contrast, loss of vegetative cover in sub-Arctic boreal forests has little impact on local temperatures. “We show that the heating in those [tropical] deforested habitats can have an effect at a very local scale,” Sinervo said. “And that means, even if you have an...