At a time of climatic anxiety, 2019 was the second warmest year since scientists began taking temperatures in 1880, government scientists announced Wednesday.
The almost record temperatures consolidated the title of the last decade as the warmest in modern human history, according to data from NASA and the National Oceanic and Atmospheric Administration. All of the last five years were among the five warmest years recorded, NASA said.
The constant increase in terrestrial and ocean temperatures throughout the world has been driven almost entirely by greenhouse gas emissions since the beginning of the Industrial Revolution.
"The decade that has just ended is clearly the warmest recorded," said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies in New York. "Every decade since the 1960s has clearly been warmer than the last."
In 2019, the average global surface temperature was 1.7 degrees above the 20th century average of 57 degrees Fahrenheit, according to NOAA measurements.
NASA set the 2019 global temperature at 1.8 degrees Fahrenheit above the 1951-80 average.
Each agency conducts its own analysis using temperature readings from thousands of terrestrial weather stations worldwide, as well as buoys floating in the oceans. Minor differences in their methods produce slight variations in numbers, but the results are on par when it comes to the pace and direction of global warming.
The last five years were exceptionally warm, with only small differences that were driven by natural variations in weather patterns, the scientists said.
"We have seen very clearly in the long term (with) many decades of temperature observations from around the world that global temperature is rising," said Noah Diffenbaugh, a climate scientist at Stanford University who was not involved in the analyzes.
In addition, he added, "the signal of that warming is very strong compared to the fluctuations from year to year and from decade to decade that occur as a result of the variability in the ocean and the atmosphere."
The rising temperature of the Earth's surface has probably played a role in the growth of certain extreme weather events, both in number and intensity. For example, scientists say warming has led to drier conditions in some areas, which could make droughts worse or increase the risk of forest fires. Higher temperatures have caused sea levels to rise, making dangerous storms more likely and causing hurricanes to shed more rain.
According to the NOAA National Environmental Information Centers, in 2019 there were 14 climatic and climatic events in the United States with losses that exceeded the $ 1 billion mark. That made it the fifth consecutive year with 10 or more billions of dollars in climate or climate disasters. (Between 1980 and 2019, the average number of such events was 6.5 per year; in the last five years, that figure soared to 13.8).
These natural disasters included floods, severe storms, tropical cyclones and forest fires. The California and Alaska wildfires that burned during the summer and fall of last year caused estimated losses of $ 4.5 billion. Large floods generated $ 20 billion in damage, and severe storms left a bill of almost $ 14 billion in its wake. In total, the 14 events resulted in losses worth $ 45 billion and 44 deaths, NOAA found.
However, President Trump fulfilled a campaign promise by initiating the formal withdrawal of the United States from the Paris climate agreement. The international agreement aims to reduce greenhouse gas emissions and limit global warming to 2 degrees Celsius (or 3.6 degrees Fahrenheit) above pre-industrial levels.