Earthweek: a Diary of the planet For the week ending Friday, Nov. 30.
The latest official report by America’s preeminent climate scientists warns that unless there are “substantial and sustained” efforts to reduce greenhouse gas emissions, climate change could eventually cost the country “hundreds of billions” of dollars per year. The stark warning issued by the National Climate Assessment was immediately dismissed by President Donald Trump. The report, issued every four years, states that climate change is already affecting the natural environment, agriculture, energy production and use, transportation and human health across the country. But with an administration that supports the fossil-fuel industry and is openly hostile toward efforts to curb greenhouse emissions, many scientists say they now feel any official U.S. action to address climate change is likely to come far too late to avoid a climate catastrophe.
Weaker currents A new study has found evidence that the ocean circulation in the North Atlantic has become the weakest of the past 1,500 years, mainly as a result of a warming climate. Many climate models predict a weakening, or even a collapse, of this branch of the ocean circulation under global warming. Researchers from the University of Hong Kong write in the journal Geophysical Research Letters that the Atlantic Meridional Overturning Circulation has far-reaching impacts on the climate from North America to Europe, and can influence the monsoon rainfall in South Asia and Africa. Canine curiosity German researchers say they have found that dogs possess “metacognitive” abilities that allow them to solve a problem when they don’t at first have enough information. The study at the Max Planck Institute created a test in which dogs had to find a reward behind one of two fences. It found that the dogs hunted for clues more often if they had not seen where the reward was hidden. The animal experts say this proves dogs have the extremely rare ability in the animal kingdom to “know what they don’t know.” Eruption An explosion caused by superheated steam at the most active volcano in the Philippines sent ash soaring above Mayon’s summit, about 200 miles southeast of Manila. Mayon last erupted in January, prompting the authorities to evacuate thousands of nearby villagers.
Global emissions of the most prevalent greenhouse gas, carbon dioxide, rose to a new historic high last year, according to a U.N. report that warns the time for action to avoid disastrous climate change is running out. It adds that emissions began rising again during 2017 for the first time in four years. Levels of accumulated atmospheric CO2 reached a global average of 405.5 parts per million during 2017, almost 50 percent higher than before the Industrial Revolution. “The last time the Earth experienced a comparable concentration of CO2 was 3 to 5 million years ago,” said World Meteorological Organization Secretary-General Petteri Taalas.