Warmest fall on record – 2015Leave a Comment
First eleven months of 2015 were fifth warmest for the Lower 48
December 9, 2015
The September-November contiguous U.S. average temperature was 56.8°F, 3.3°F above the 20th century average, surpassing the previous record of 56.6°F set in 1963. Record and near-record warmth spanned much of the nation. The November contiguous U.S. temperature was 44.7°F, 3.0°F above the 20th century average and the 13th warmest in the 121-year period of record. The autumn precipitation total for the contiguous U.S. was 8.32 inches, 1.44 inches above the 20th century average. This was the 15th wettest September-November on record for the Lower 48 and the wettest since 2004. The November precipitation total was the fourth wettest on record with 3.30 inches, 1.07 inches above average. Record and near-record precipitation was observed across the Great Plains and Southeast. This monthly summary from NOAA’s National Centers for Environmental Information is part of the suite of climate services NOAA provides to government, business, academia and the public to support informed decision-making…
Posted: 09 Dec 2015 11:44 AM PST
The impact of climate change may be worse than previously thought, a new study suggests. As world leaders hold climate talks in Paris, research shows that land surface temperatures may rise by an average of almost 8C by 2100, if significant efforts are not made to counteract climate change. Such a rise would have a devastating impact on life on Earth. It would place billions of people at risk from extreme temperatures, flooding, regional drought, and food shortages. The study calculated the likely effect of increasing atmospheric levels of greenhouse gases above pre-industrialisation amounts. It finds that if emissions continue to grow at current rates, with no significant action taken by society, then by 2100 global land temperatures will have increased by 7.9C, compared with 1750. This finding lies at the very uppermost range of temperature rise as calculated by the Intergovernmental Panel on Climate Change. It also breaches the United Nations’ safe limit of 2C, beyond which the UN says dangerous climate change can be expected. Research at the University of Edinburgh first created a simple algorithm to determine the key factors shaping climate change and then estimated their likely impact on the world’s land and ocean temperatures. The method is more direct and straightforward than that used by the IPCC, which uses sophisticated, but more opaque, computer models. The study was based on historical temperatures and emissions data. It accounted for atmospheric pollution effects that have been cooling Earth by reflecting sunlight into space, and for the slow response time of the ocean.
Its findings, published in Earth and Environmental Transactions of the Royal Society of Edinburgh, may also help resolve debate over temporary slow-downs in temperature rise.
Professor Roy Thompson, of the University of Edinburgh’s School of GeoSciences, who carried out the study, said: “Estimates vary over the impacts of climate change. But what is now clear is that society needs to take firm, speedy action to minimise climate damage.”
Roy Thompson. Climate sensitivity. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 2015; DOI: 10.1017/S1755691015000213
A milestone year?
Nature Climate Change Editorial
6, 1 (2016) doi:10.1038/nclimate2911 Published online 23 December 2015
2015 began with the warmest winter on record on a global scale, and ended as the hottest year since records began, with average global temperatures reaching 1 °C above pre-industrial levels for the first time1. But these were not the only records broken this year, as a large number of extreme-intensity events unfolded. The winter snowpack in California hit a record low, prolonging one of the most severe and longest droughts in the USA2. El Niño appeared shyly in May and then went on to become a monster, heating up the equatorial Pacific ocean by more than 3 °C by November3. Tropical cyclone Patricia went off the hurricane category scale with winds of over 320 km per hour, and the Arabian peninsula was hit by two consecutive cyclones — an unprecedented occurrence in the climate record of the region1.
It is clear that many different factors have contributed to these events, and care must be taken before linking any particular event to climate change. But one thing is sure: human influence has significantly increased the likelihood of extremes4.
Extreme weather has the power to change people’s perception of climate change — as happened after extensive flooding in England over the winter of 2013/145. The unprecedented events of this past year prompted many world and religious leaders to make important public announcements to raise awareness on the seriousness of the issue. It is in this context that the international climate negotiations in Paris took place, where a global deal for the future of the planet was being discussed as these very words were being written. Such events make one thing clear: time is at a premium. Global average atmospheric CO2 concentrations have indefinitely passed the 400 ppm mark6, reflecting the relentless increase in emissions. This puts us on a fast track to 2 °C of warming, which is considered to be a dangerous climate change threshold beyond which even more extreme events can be expected. If 2015 was a year full of climate milestones, 2016 has the potential to be another: the year when global society took firm and collective action to begin changing the dangerous path that we are currently treading. It is certainly a big New Year’s resolution.