Last year was one of the warmest years on record with record high sea levels, destructive coral bleaching, and some of the highest greenhouse gas emissions ever. It comes in just behind 2016, the hottest year on record, and 2015, the second hottest. Excluding El Niño – a periodic climatic event that boosts temperatures in the Pacific Ocean – 2017 is the hottest year to date.
The National Oceanic and Atmospheric Administration (NOAA) released its findings in the 28th annual State of the Climate Report published in the Bulletin of the American Meteorological Society. The yearly "checkup for the planet” is compiled by more than 500 scientists in 65 countries who monitor environmental data on global climate indications and extreme weather events.
The doctors have some unfortunate news.
Nearly every month this year has sent the mercury soaring over normal or average temperatures and that trend was seen in 2017 as well. Global land and ocean surface temperatures reached near-record highs, making 2017 either the second or third warmest year depending on the data set. After 1901, the surface of the planet warmed by as much as 0.9°C (1.6°F) over the century, with the rate doubling in 1975. In fact, the 10 warmest years on record have occurred since 1998, with four of the warmest years taking place after 2014.
Last year, Spain, Bulgaria, Argentina, and Mexico all broke annual temperature highs, with Puerto Madryn in Argentina experiencing the highest temperature "ever recorded so far south anywhere in the world." The record for the highest April temperature recorded on Earth was broken recently in Nawabshah, Pakistan, where it was 50.2ºC (122.4ºF).
Consequences of the heat are felt all over the world. Last year, maximum sea ice coverage fell to a record low in the Arctic. Meanwhile In Antarctica, on March 1, 2017, sea ice fell to 2.1 million square kilometers (811,000 square miles) – the lowest daily amount observed since satellite records began in 1978.
As sea surface temperatures continue to get warmer, “unprecedented” coral bleaching keeps occurring. According to the report, a global three-year-long bleaching event in 2014 killed as much as 95 percent of the coral on certain reefs and in some parts of the world, it’s not expected to recover.
Above-average numbers of tropical cyclones occurred last year as well. As many as 85 tropical cyclones were named, just slightly above the 30-year average of 82. Weather and climate-related disasters cost the US $306 billion in 2017, surpassing the previous record of $215 billion in 2005 following hurricanes Katrina, Wilma, and Rita.