Despite the global commitment to climate change mitigation, GHG emissions have continued to grow, reaching record highs in 2017. This is one of the key findings of the State of the Climate 2017 report, published by the U.S. National Oceanic and Atmospheric Administration (NOAA). Over 500 researchers from 65 countries contributed to the report, documenting weather phenomena and developments in the global climate. 2017 ranked among three of the warmest years since modern recording-keeping began in 1880. Globally it was, characterized by soaring temperatures, coral bleaching, melting glaciers, retreating sea ice and a rising sea level.
According to the report several countries, including Argentina, Uruguay, Portugal, Spain, and Bulgaria, reported record high annual temperatures, while Mexico experienced this for the fourth consecutive year. High temperatures were also observed in the Arctic and northwestern Canada. These rising temperatures have led to a drop in Arctic sea ice mass. Satellite measurements in March 2017 indicate that the maximum extent of Arctic sea ice was eight percent below the 1981-2010 mean. This marks the lowest maximum extent in 38 years. Glaciers across many parts of the world have declined in mass, a trend that has continued with high regional consistency.
Soaring temperatures also triggered coral reef bleaching. The coral bleaching event lasted between 2014 and 2017 and scientists consider it as the longest and most destructive on record. Corals can tolerate high temperatures for only short periods. Prolonged high temperatures stress the corals causing them to wither and die.
There were also several extreme precipitation events. For example, in Russia, India, Nigeria, Venezuela, Jamaica, and Martinique. In the Caribbean, tropical cyclones and hurricanes Irma, Jose and Maria caused excessive rainfall. María caused the greatest damage after Katrina and Harvey in the United States. These damages spread across Puerto Rico and the U.S. Virgin Islands, and it has been the strongest hurricane to impact Puerto Rico since 1928.
2017 was the warmest year not influenced by El Niño, the periodic warming of the oceans.