As all-time temperature records continue to be broken in heat waves around the Northern Hemisphere this summer, scientists say there has never been a time in the past 2,000 years when global temperatures have risen so quickly.
June 2019 was the hottest on record, and July is likely to be the hottest as well.
Scientists in three separate reports say that while the world has warmed and cooled many times over the centuries, soaring greenhouse gas emissions are resulting in a climate that is now warming as never seen before.
“This paper should finally stop climate change deniers claiming that the recent observed coherent global warming is part of a natural climate cycle,” said Mark Maslin, professor of climatology at University College London, who wasn’t part of the studies.
One of the lead authors says the scientific consensus that human activity is behind global heating is likely to have surpassed 99%.
Oceans Are Melting Glaciers from Below Much Faster than Predicted
Beneath the ocean’s surface, glaciers may be melting 10 to 100 times faster than previously believed, new research shows.
Until now, scientists had a limited understanding of what happens under the water at the point where ice meets sea. Using a combination of radar, sonar and time-lapse photography, a team of researchers has now provided the first detailed measurements of the underwater changes over time. Their findings suggest that the theories currently used to gauge glacier change are underestimating glaciers’ ice loss.
The warming atmosphere melts glaciers from above, while ocean water can erode the ice along the glacier’s face. Researchers have been studying similar effects of ocean water beneath the ice shelves in Antarctica, which slow the flow of the glaciers on land behind them. Last year, a study there found that warming ocean waters are contributing to glacial changes that increase the rate of sea level rise.
As fresh water from melting glaciers enters the ocean, it does more than increase sea level. “Plumes” of fast-moving runoff stir up nutrients locked deep in the water, which then feed phytoplankton and zooplankton near the surface, spurring population booms.
Changes in tidewater glaciers can have an impact on people living along the Alaskan coast, altering patterns in the ocean water that provides food and livelihood for many. Longer melt seasons mean more fresh water entering the ocean earlier in the year. This could affect things like salmon swimming up those streams or not.