According to the combined analysis of leading international data sets carried out by the World Meteorological Organization, 2019 was the second warmest year in the history of observations after 2016, according to the WMO Internet portal.
The average temperatures for the five-year (2015–2019) and ten-year (2010–2019) periods were the highest in the entire history of observations. Since the 1980s, each of the decades has been warmer than the previous one. This trend is expected to continue due to record high levels of heat-retaining greenhouse gases in the atmosphere.
In 2019, the average annual temperature over all five sets of data used in the summary analysis was 1.1 ° C higher than the average annual temperature for the period from 1850 to 1900, which was used to reflect “pre-industrial” conditions. The warmest year in the history of observations remains 2016, due to a combination of the very powerful El Niño phenomenon leading to warming and long-term climate change.
“The average annual temperature has risen by about 1.1 °C compared to the pre-industrial period, and the ocean temperature is at a record high,” said WMO Secretary-General Petteri Taalas. “At the current level of carbon dioxide emissions, by the end of the century, temperature will rise by 3-5 degrees Celsius.”
However, temperatures only partially indicate what is happening. The last year and decade were characterized by ice retreat, record high sea levels, rising temperatures and ocean acidification, and extreme weather events. As highlighted in the WMO preliminary statement on the state of the global climate in 2019, which was presented at the UN Climate Change Conference in Madrid, the combination of these phenomena has had a serious impact on the health and well-being of both humans and the environment. The full text of the statement will be published in March 2020.
“2020 began with what ended the year 2019 – with meteorological and climatic events with significant consequences. In Australia, the year 2019 was the hottest and driest in the history of observations, creating conditions for the most powerful forest fires that became so devastating for people and property, wildlife, ecosystems and the environment,” said Taalas.
“Unfortunately, in 2020 and in the coming decades, we expect a large number of extreme weather events caused by record high levels of heat-holding greenhouse gases in the atmosphere,” he said.
More than 90% of the excess heat is stored in the oceans, so the heat content of the ocean is a good way to quantify the rate of global warming. A new study, published January 13 in the publication of Advances in Atmospheric Sciences and containing data from the National Center for Environmental Information/National Oceanic and Atmospheric Administration and the Institute of Atmospheric Physics, showed that in 2019 the ocean’s heat content was at a record level. The last five years have become the warmest in history in terms of ocean temperature according to measurements of modern instruments, and the last ten years are also the warmest in the history of observations.