Tag Archives: climate change

How hot was June 2021?

From NOAA’s Global Climate Report – June 2021:

The June 2021 global surface temperature was the fifth highest for June in the 142-year record at 0.88°C (1.58°F) above the 20th century average. Only Junes of 2015 (fourth warmest), 2016 (second warmest), 2019 (warmest), and 2020 (third warmest) were warmer and had a global temperature departure above +0.90°C (+1.62°F). Nine of the 10 warmest Junes have occurred since 2010.

But June seemed hot you say? Yup:

The global land-only surface temperature for June 2021 was the highest on record at 1.42°C (2.56°F) above average. This value surpassed the previous record set in 2019 by +0.11°C (+0.20°F). The ten warmest June global land-only surface temperatures have occurred since 2010. The unusually warm June global land-only surface temperature was mainly driven by the very warm Northern Hemisphere land, which also had its highest June temperature departure at +1.69°C (+3.04°F). The now second highest June temperature for the Northern Hemisphere occurred in 2012 (+1.51°C / +2.72°F).

Time series data is available at the link near the top of the page.


How hot was the Pacific Northwest?

Berkeley Earth summarizes the recent heatwave in the Pacific Northwest in the article The Pacific Northwest Heatwave in Context  (7/6/2021). The graph by Dr. Robert Rohde copied here is striking and really says all that needs to be said. This is a graph that everyone should have to study and understand. This was anything but a typical heatwave.

There are other graphs and links to dedicated data pages for Washington State, Oregon, Seattle, Portland, Vancouver, and Canada. On these pages there are more graphs and links to the data that created the graphs.

What do we know about hurricanes?

The article NASA and Hurricanes: Five Fast Facts by Katy Mersmann (6/1/2021) has the answers.

The 2021 Atlantic hurricane season starts today, June 1. Our colleagues at NOAA are predicting another active season, with an above average number of named storms. At NASA, we’re developing new technology and missions to study storm formation and impacts, including ways to understand Earth as a system.

The third fact:

Climate change is likely causing storms to behave differently. One change is in how storms intensify: More storms are increasing in strength quickly, a process called rapid intensification, where hurricane wind speeds increase by 35 mph (or more) in just 24 hours.

In 2020, a record-tying nine storms rapidly intensified. These quick changes in storm strength can leave communities in their path without time to properly prepare.

Researchers at NASA JPL developed a machine learning model that could more accurately detect rapidly intensifying storms.

There are fantastic images (such as the one copied here – incorporate it into a Calc III course?) and short videos. Climate.gov has a starting point for hurricane data: Historical Hurricane Tracks – GIS Map Viewer.  A past post on hurricanes: Are hurricanes lingering near the coast longer?


What’s new at the EPA?

After about a 4 year hiatus, the EPA’s page Climate Change Indicators in the United Stats has been updated with “Twelve new indicators and several years of data have been added to EPA’s indicator suite.” One new indicator is Permafrost:

The Deadhorse site in northern Alaska had the highest rate of temperature change, at +1.5°F per decade. The Livengood site in interior Alaska was the only site to get cooler over the period of record, though only slightly. Overall, permafrost temperatures have increased at an average rate of 0.6°F per decade.

There are csv files to download the data and background information about the indicators. This is an excellent resource page.

Where are the 1991-2020 U.S. Climate Normals?

NOAA has this data on the 1991-2020 U.S. Climate Normals Quick Access page.

The 2020 U.S. Climate Normals Quick Access tool provides access to data from the most recent version of the U.S. Climate Normals. This iteration of the Normals product provides 30 year averages of temperature, precipitation, and other climate variables measured at more than 15,000 U.S observation stations from 1991–2020, as well as a set of 15 year supplemental normals for 2006–2020.

The image here is a screen shot of monthly normals for one of the Ithaca, NY locations. On the top right corner of the graph there is a link to download the data, which is also in a table below the graph.

How hot was March 2021

From NOAA’s Global Climate Report – March 2021:

Following a strongly negative Arctic Oscillation (AO) in February 2021, a strongly positive AO was present in March 2021. In a positive phase, the jet stream strengthens and circulates the North Pole, confining the cold Arctic Air across the Polar Regions. The AO value for March 2021 was 2.11—the fifth highest March value since 1950. The peak value on March 11 was the ninth highest daily value and the third highest for a day in March. In addition, during March 2021, La Niña continued to be present across the tropical Pacific Ocean; however, it weakened in strength.

The global surface temperature departure of +0.85°C (+1.53°F) in March 2021 was the smallest March temperature departure since 2014 and was the eighth highest for March in the 142-year record. March 2021 also marked the 45th consecutive March and the 435th consecutive month with temperatures, at least nominally, above the 20th-century average.

The data is available near the top of the page under Temperature Anomalies Time Series.

How do humans impact the earth’s energy balance?

The NASA article, Direct Observations Confirm That Humans Are Throwing Earth’s Energy Budget off Balance, by Sofie Bates (3/25/21) explains:

Climate modelling predicts that human activities are causing the release of greenhouse gases and aerosols that are affecting Earth’s energy budget. Now, a NASA study has confirmed these predictions with direct observations for the first time: radiative forcings are increasing due to human actions, affecting the planet’s energy balance and ultimately causing climate change. The paper was published online on March 25, 2021, in the journal Geophysical Research Letters.

“This is the first calculation of the total radiative forcing of Earth using global observations, accounting for the effects of aerosols and greenhouse gases,” said Ryan Kramer, first author on the paper and a researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, Baltimore County. “It’s direct evidence that human activities are causing changes to Earth’s energy budget.”

The human impact:

The team found that human activities have caused the radiative forcing on Earth to increase by about 0.5 Watts per square meter from 2003 to 2018. The increase is mostly from greenhouse gases emissions from things like power generation, transport and industrial manufacturing. Reduced reflective aerosols are also contributing to the imbalance.

No data in this one, but it provides a good overview of the paper.

Is there a polar vortex climate change connection?

When the Arctic polar vortex is especially strong and stable (left globe), it encourages the polar jet stream, down in the troposphere, to shift northward. The coldest polar air stays in the Arctic. When the vortex weakens, shifts, or splits (right globe), the polar jet stream often becomes extremely wavy, allowing warm air to flood into the Arctic and polar air to sink down into the mid-latitudes. NOAA Climate.gov graphic, adapted from original by NOAA.gov.


The climate.gov article Understanding the Arctic polar vortex by Rebecca Lindsey (3/5/2021) is a complete primer on the polar vortex, jet stream, and what we know (and don’t) abut the connection to climate change.

According to NOAA stratosphere expert Amy Butler, people often confuse the polar vortex with the polar jet stream, but the two are in completely separate layers of the atmosphere. The polar jet stream occurs in the troposphere, at altitudes between 5-9 miles above the surface. It marks the boundary between surface air masses, separating warmer, mid-latitude air and colder, polar air. It’s the polar jet stream that plays such a big role in our day-to-day winter weather in the mid-latitudes, not the polar vortex.

Any relationships to climate change is unclear, for example:

The uncertainty due to a relatively short history of observations isn’t the only reason experts can’t dismiss the possibility that something could be up with polar vortex. Some climate model experiments do predict that continued warming will lead to a weakening of the polar vortex. “It’s true that when you run some high-resolution climate models, with a realistic stratosphere, and a realistic sea ice layer, and you reduce sea ice cover, these models predict that the polar vortex gets weaker,” Butler said. And some studies combining models and observations have shown a connection between low sea ice extent in the Barents and Kara Seas of the eastern Arctic, sudden stratospheric warming events, and cold winters in North America.

At the same time, other model simulations predict that warming and sea ice loss will lead to a stronger polar vortex. Part of the reason for the disagreement is that the impact of Arctic surface warming and sea ice loss on the atmospheric waves that can disrupt the polar vortex is very sensitive to exactly where and when the sea ice loss occurs, and that hasn’t been consistent across model simulations.

No data in this article but there are some useful graphs, such as the one copied here, and the article is just generally interesting.

How hot was Jan 2021?

For NOAA’s Global Climate Report – January 2021:

The January 2021 global land and ocean surface temperature was 0.80°C (1.44°F) above the 20th century average and ranked as the seventh warmest January in the 142-year global records. January 2021 also marked the 45th consecutive January and the 433rd consecutive month with temperatures, at least nominally, above the 20th-century average.

Only 7th warmest but

The year began with a La Niña episode in the tropical Pacific Ocean that started in August 2020. The El Niño-Southern Oscillation (ENSO) can affect global temperatures. La Niña tends to cool global temperatures slightly, while El Niño tends to boost global temperatures. With a slightly cool start to the year, there is only a 2.9% chance of 2021 ending as the warmest year on record. However, there is an over 99% chance of the year ranking among the 10 warmest years on record.


According to NCEI’s regional analysis, North America, as a whole, had its second warmest January on record, with a temperature departure from average of +3.96°C (+7.13°F). This was only 0.10°C (0.18°F) shy of tying the record warm January set in 2006.


As a whole, about 5.93% of the world’s surface had a record-warm January temperature–the third highest January percentage since records began in 1951. Only Januarys of 2016 (15.73%) and 2020 (7.05%) had a higher percentage of record warm January temperatures. Meanwhile, much of northern Asia was at least 2.0°C (3.6°F) colder than average, in stark contrast to most of 2020, when the region was well above average.

As always the report is worth reading and the data in the graph is available.

What are U.S. predicted energy CO2 emissions?

The eia article EIA’s AEO2021 shows U.S. energy-related CO2 emissions rising after the mid-2030s by Perry Lindstrom and Kevin Nakolan (2/11/2021) provides the graph copied here.

EIA projects that U.S. energy-related CO2 emissions will increase in the latter years of the projection as a result of increasing economic growth that leads to growing industrial energy requirements. EIA projects energy use in transportation will increase as vehicle fuel efficiency plateaus in the mid-2020s and becomes outweighed by increases in vehicle travel demand.

There are links to data in the article.