Berkeley Earth Global Temperature Update: 2020 Was Second Warmest Year Since 1850
Berkeley, Calif. — Berkeley Earth today released its Global Temperature Report for 2020, concluding that the year was nominally the second warmest on Earth since 1850 based on land and ocean data.
Globally, 2020 was slightly cooler than and nearly tied with 2016. However, 2020 was definitively the warmest year on record for land temperatures, nearly 2 degrees Celsius above the pre-industrial average. Other organizations examining 2020 temperatures are expected to report similar results, though there are occasionally minor differences in the overall rankings. Berkeley Earth draws upon the largest number of temperature stations and has more complete coverage.
“Year-to-year rankings are likely to reflect short-term natural variability,” said Berkeley Earth Lead Scientist Dr. Robert Rohde. “But the overall pattern remains consistent with a long-term trend toward global warming.”
The California-based nonprofit research organization, founded by Elizabeth and Richard Muller in 2013 to address skepticism around global warming, is the world’s only non-governmental source of independent climate change and air pollution data.
As the report notes, the last six years stand out from the previous 164 years as an unprecedented period of significant warmth. Though 2020 ended up being just slightly cooler than 2016, the results remain consistent with the overall warming trend.
In addition to long-term warming, individual years are also affected by interannual variations in weather.
Both 2015 and 2016 were warmed by an extreme El Niño event that peaked in Nov./Dec. of 2015 and was reported by NOAA as essentially tied for the strongest El Niño ever observed. That exceptional El Niño boosted global mean temperatures in 2015 and 2016.
By contrast, 2020 began with neutral conditions and finished with a moderate La Niña. The La Niña would have been expected to somewhat reduce temperatures in 2020 and is likely to have a large impact on 2021.
Internal weather variability, such as El Niño and La Niña, generate year-to-year variations in temperature that occur in addition to the long-term warming trend. The fact that despite a La Niña 2020 nearly tied the super El Niño warmth of 2016 is emblematic of how fast climate change is progressing.
To better understand climate change in 2020, Berkeley Earth analyzed data from 19,000 weather stations and 19 million observations of the ocean, comparing them to an even larger collection of historical averages. This analysis built a map of conditions in 2020 showing that 87 percent of the Earth’s surface was significantly warmer than the average temperature from 1951 to 1980. Twelve percent was of a similar temperature and only 1.3 percent was significantly colder. In addition, 10 percent of the Earth set new record highs for annual average temperature. No locations had a record low annual average.
Looking at national averages, 2020 was the warmest since record-keeping began in 41 countries and the warmest year ever observed in Europe and Asia.
Warming was nowhere more evident last year than in Northern Asia, with extraordinary new records for warmth in Siberia, Rohde said, contributing to a cycle of Arctic sea ice melt that only leads to additional warming.
“At the current rate of progression, the increase in Earth’s long-term average temperature will reach 1.5 °C (2.7 °F) above the 1850-1900 average by around 2035, and 2 °C (3.6 °F) will be reached around 2065,” Rohde said. “The increasing abundance of greenhouse gases in the atmosphere due to human activities is the direct cause of this recent global warming. If the Paris Agreement’s goal of no more than 2 °C (3.6 °F) warming is to be reached, significant progress toward reducing greenhouse gas emissions needs to be made soon.”
“Berkeley Earth was created to provide independent investigation of global warming and other major environmental problems,” remarked Berkeley Earth President and co-founder Elizabeth Muller. “We are the only non-government entity providing global temperature analysis, and this independence matters. Objective data rather than politics must form the basis for our understanding of the issue, as well as for sound decision-making. I am deeply concerned about global warming, and we must have a thoughtful and data-driven approach to how it can be addressed and mitigated.”
The full report can be found here.
About Berkeley Earth
Open-source from the outset, Berkeley Earth’s data sets are differentiated by a more flexible, inclusive approach for analyzing temperature observations, allowing us to incorporate data from a greater number of the world’s temperature stations. Created around our values of independence, impartiality, scientific excellence, and open-source science, our unique handling of interpolation and systematic biases helps to ensure the most detailed picture of climate change. Trusted by the UN IPCC in its 2018 and 2019 Special Reports on Global Warming, and cited in more than 1,800 scholarly and academic papers, our surface temperature data sets are foundational to research, policy, and education. We continue to update our data sets monthly, ensuring open-source access to the highest-quality global temperature data.