What’s New

by Richard A. Muller and Elizabeth A. Muller For many people, comparing air pollution to cigarette smoking is more vivid and meaningful than is citing the numbers of yearly deaths. When we published our scientific paper on air pollution in China in August 20151, we were surprised by the attention we got for a quick […]

Earlier this month the Shenyang EPA reported the worse levels of air pollution since record keeping began: Estimates varied between 1000 and 1400 micrograms per cubic meter of PM2.5— the fine particulate matter that has deadly health consequences. The US embassy in Shenyang reported “off the chart” recordings. In our recent study in PLOS on […]

Berkeley Earth released our annual Global Temperature Report for 2020, including findings that 2020 was the second warmest year on record. Thanks to our partners in the media, the independent research, data, and findings we presented in this report have reached an audience of nearly 400 million worldwide. One highlight of our impact: Berkeley Earth’s […]

Berkeley Earth, a California-based non-profit research organization, has been preparing independent analyses of global mean temperature changes since 2013. The following is our report on global mean temperature during 2020. We conclude that 2020 was nominally the second warmest year on Earth since 1850. Our estimate of the global mean temperature in 2020 was slightly […]

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. […]

Cooling weather may have caused increased COVID-19 spread. Considered across many regions, the average reproduction number (R) gradually increased from ~1.0 to ~1.2 as daily high temperatures fell from >27 °C to ~10-15 °C (>80 °F to 50-60 °F). Other factors, including decreases in sunlight and/or UV exposure, may have slightly increased this further.

While our fully open-source surface temperature datasets have been publicly available for some time, this paper represents the first time our complete detailed methodology has been formally published. The paper specifically includes discussion of Berkeley Earth’s treatment of air temperature in the Arctic region, and provides visualization of the global warming trends suggested by Berkeley Earth’s dataset vs. other global temperature records.

As an eventful year of climate news comes to a close, Berkeley Earth climate scientists Dr. Robert Rohde and Dr. Zeke Hausfather talk with Social Media Manager Kari Hulac about air surface temperature records and the significant warming event in the Arctic region, as well as preview some exciting new research about climate change mitigation efforts.

Congratulations are in order for Berkeley Earth’s sister organization Deep Isolation, who announced today the closing of a $20m Series A funding round, led by nuclear industry leaders NAC International. Founded by Berkeley Earth Co-Founder and President Elizabeth Muller, Deep Isolation is developing a patented process to safely dispose of nuclear waste, a major issue […]

Globally, October 2020 was the fifth warmest October since record-keeping began in 1850. La Niña conditions strengthened in October, significantly reducing the likelihood that 2020 sets a new record for warmest year.

Globally, September 2020 is found to be the warmest September since records began in 1850. There is now a 57% chance that 2020 finishes as the warmest year on record.

In this midst of a record-setting fire season, Berkeley Earth’s climate scientists Robert Rhode and Zeke Hausfather talk with Social Media Manager Kari Hulac to discuss climate change and the fires burning across the West.

An earlier version of this article originally appeared on the Asthma Allergies Children website. By Liz Muller As I write this white ash is visible in the polluted San Francisco Bay Area air, wafting down from a smoky orange sky and into our lungs, a dangerous byproduct of wildfires burning more than 3 million acres […]

Globally, July 2020 is estimated to have been tied with July 2019 as the warmest July since records began in 1850. The nominal difference between 2019 and 2020 is less than 0.01 °C, which is much smaller than the uncertainty on this temperature analysis, making 2019 and 2020 indistinguishable. Previously in 2020, we have also witnessed the warmest April, May, and June.

Globally, June 2020 is estimated to have been the warmest June since records began in 1850, exceeding the previously warmest year in 2019. However, the margin of difference between 2020 and 2019 is small compared to the estimated uncertainties. As a result June 2020 and June 2019 may be regarded as essentially tied for the warmest June. 2020 has also had both the warmest April & May.

Globally, May 2020 is estimated to have been the warmest May since records began in 1850, exceeding the previously warmest year in 2016. This follows the warmest April. Updated projections for the rest of 2020 give a 89% chance that 2020 will be a new record warm year, a significant increase relative to prior projections.

As noted above, the current projection for 2020 has shifted significantly higher than previous projections. The resulting ~60% chance of a new record is similar to projections that others have issued for 2020.

Globally, March 2020 is estimated to have been the fourth warmest March since records began in 1850. March 2020 was appreciably cooler than March 2016, and slightly cooler than March in 2017 and 2019. However, March 2020 remains warmer than all other Marchs since global temperature estimates began in 1850. This follows the 2nd warmest February and 2nd warmest January.

Warming weather is unlikely to stop the spread of the pandemic. Warm, sunny weather may have some limited impact on the rate of spread, but in the absence of strong interventions, the pandemic is likely to continue spreading through the summer months in most parts of the world.

Berkeley Earth, a California-based non-profit research organization, has been preparing independent analyses of global mean temperature changes since 2013. The following is our report on global mean temperature during 2019. We conclude that 2019 was the second warmest year on Earth since 1850. The global mean temperature in 2019 was colder than 2016, but warmer […]

The following is a summary of global temperature conditions in Berkeley Earth’s analysis of November 2019. Globally, November 2019 was the second warmest November since records began in 1850. The global mean temperature was 0.88 ± 0.05 °C above the 1951 to 1980 average.  This is equivalent to being 1.26 ± 0.07 °C above the 1850 to 1900 average, […]

The following is a selected list of third-party data visualizations that have used data from Berkeley Earth. Climate Data Data explorer map of past and future temperature change produced by Carbon Brief. Local changes in the number of hot days produced by The New York Times. Temperature change in major cities produced by the BBC. […]

The following is a summary of global temperature conditions in Berkeley Earth’s analysis of October 2019. Globally, October 2019 was the second warmest October since records began in 1850. The global mean temperature was 0.99 ± 0.06 °C above the 1951 to 1980 average.  This is equivalent to being 1.38 ± 0.07 °C above the 1850 to 1900 average […]

Berkeley Earth, a California-based non-profit research organization, has been preparing independent analyses of global mean temperature changes since 2013. The following is our report on global mean temperature during 2018. We conclude that 2018 was likely the fourth warmest year on Earth since 1850. Global mean temperature in 2018 was colder than 2015, 2016, and […]

Berkeley Earth, a California-based non-profit research organization, has been preparing independent analyses of global mean temperature changes since 2013. The following is our report on global mean temperature during 2017. We conclude that 2017 was likely the second warmest year on Earth since 1850. Global mean temperature in 2017 was 0.03 °C (0.05 °F) warmer […]

Horrific Air Pollution in Europe Reaches 7 cigarettes per day equivalent, a pack a day in India and China It’s winter, and that’s the worst air pollution period for Europe and China. The levels over much of the continent are in the unhealthy range. In the figure we show a map of the pollution of […]

2016 was the warmest year since humans began keeping records, by a wide margin. Global average temperatures were extremely hot in the first few months of the year, pushed up by a large El Nino event. Global surface temperatures dropped in the second half of 2016, yet still show a continuation of global warming. The […]

by Zeke Hausfather Air pollution in China is a critical global health problem, responsible for somewhere between 700,000 and 2.2 million premature deaths annually. The largest single contributor to air pollution-related mortality is particulate matter below 2.5 microns in size, or PM2.5. Exposure to PM2.5 has been found to increase the risk of heart attacks, […]

by: Zeke Hausfather, Berkeley Earth zeke@berkeleyearth.org The relationship between greenhouse gas (GHG) emissions and future warming is complex, depending on the atmospheric lifetime of gases, their radiative forcing, and the thermal inertia of the Earth, particularly our oceans. Many non-CO2 GHGs have shorter atmospheric lifetimes, and the global warming-equivalent values commonly used for analysis of emission […]

On May 1, 2016, a fire began southwest of Fort McMurray,  Canada. It swept through the community destroying over 2000 structures. You can read about the latest developments here. Since 2014 Berkeley Earth has been expanding its real time database of air pollution. Our original focus was on China, but we have continued to add other regions of […]

By Zeke Hausfather In recent weeks we’ve seen a political controversy over NOAA’s adjustments to temperature records, with accusations from some in congress that records are being changed to eliminate a recent slowdown in warming and to lend support to Obama administration climate policies. This makes it sound like the NOAA record is something of […]

Over the past few days we have been publishing the first major update of our data since early 2015. The data can be found here on our data page. Given the time of year and the wide ranging discussion about whether or not 2014 was a record year, it seemed a good time to asses […]

As the AP  reports  Lelieveld has published a paper in Nature  on the mortality associated with outdoor air pollution that  confirms what BerkeleyEarth found in its study of air pollution in China. By their estimate   ~1.357M deaths in China are caused by air pollution. By our estimate there are ~1.6 Million deaths per year in China […]

In our study of air pollution in China, we stumbled upon two extraordinary days.  The first, which we initially thought was a fluke, turned out to be a single day when air pollution across China was more extensive than we had seen in a years worth of data.  It was a mystery until  lead scientist, […]

Can natural gas help us reduce climate change by acting as a bridge fuel away from coal? New research from Berkeley suggests that it can, even if it modestly delays the date at which we switch to renewables. The U.S. is in the midst of a natural gas boom. The combination of horizontal drilling and […]

Mountains of ink have been spilled in recent years on whether or not global warming has paused or slowed down. We’ve discussed it extensively in the past, and numerous studies have examined whether the apparent pause might have been caused by additional ocean heat uptake, small volcanoes, a weak solar cycle, poor arctic coverage in existing datasets, and\or a […]

There has been much discussion of temperature adjustment of late in both climate blogs and in the media, but not much background on what specific adjustments are being made, why they are being made, and what effects they have. Adjustments have a big effect on temperature trends in the U.S., and a modest effect on […]