climate system

A record warm January

March 4, 2025 By EarthWise Leave a Comment

Americans experienced unusually cold and wintery weather in January. Places like southern Louisiana and Florida saw appreciable amounts of snow. For those who experienced January’s Arctic blast, it was a cold January. But despite that, January was the world’s warmest on record, extending a run of extraordinary heat in which 18 out of the last 19 months saw an average global temperature more than 1.5 degrees Celsius above pre-industrial times. In fact, the global average temperature in January was 1.75 degrees above the pre-industrial average.

The exceptional warmth was surprising to climate researchers. It happened despite the emergence of La Niña conditions in the Pacific Ocean, which tend to lower global temperatures, at least for a while.

Researchers are investigating whether there is something beyond the effects of greenhouse gas emissions that is boosting temperatures to an unexpected degree. It is true that emissions, associated with the burning of coal, gas, and oil, reached record levels in both 2023 and 2024. But January’s warmth was still something of a surprise.

One prevalent theory is that cutting dangerous pollution is playing a role in causing global warming to accelerate. As regulators have curbed sulfate pollution to protect people’s lungs, the cooling effect of these particles that help form more and brighter clouds has diminished.

January demonstrates that the global climate system is complex and the weather in any particular region does not necessarily reflect what is happening to the planet as a whole.

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Global Temperatures Shattered Records in January

Photo, posted December 22, 2013, courtesy of SD Anderson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Renegade geoengineering

October 30, 2024 By EarthWise Leave a Comment

As the dangers of climate change continue to grow, so has interest in geoengineering – deliberate tinkering with the earth’s climate system. In particular, stratospheric solar geoengineering – releasing aerosols into the stratosphere to reduce the amount of heat from the sun reaching the Earth – is attracting increasing interest. Scientists at Harvard, Cornell, Colorado State, Princeton, and the University of Chicago are all researching the topic.

Actually doing it on a scale that matters is fraught with peril from unintended consequences of disrupting the delicate interactions between the Earth’s atmosphere, ocean, land, and sea ice.

Meanwhile, a tiny start-up company in Silicon Valley has raised more than a million dollars in venture capital and is busy releasing balloons full of sulfur dioxide into the atmosphere in the name of combatting global warming. Furthermore, they are selling so-called “cooling credits” to customers who want to offset their personal carbon emissions.

The aerosol being released is on such a small scale that it can’t possibly have a meaningful effect on temperatures. There really isn’t scientific analysis guiding or accompanying the work.

There are no laws prohibiting the dispersal of small amounts of sulfur dioxide in California. Even if there were, these people could go offshore or elsewhere to do their work. But this renegade geoengineering highlights a serious issue; namely, that there doesn’t have to be scientific, political, or any other kind of consensus for someone to undertake a potentially catastrophic attempt to alter the climate. It’s a real worry.

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Silicon Valley Renegades Pollute the Sky to Save the Planet

Photo, posted September 24, 2006, courtesy of Doc Searls via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildfires And The Climate | Earth Wise

September 24, 2021 By EarthWise Leave a Comment

Scientists from the National Center for Atmospheric Research recently published a study analyzing the events that influenced the world’s climate in 2020. Among these were the pandemic-related lockdowns that reduced emissions and resulted in clearer air in many of the world’s cities.

While this was a significant event, the study found that something entirely different had a more immediate effect on global climate: the enormous bushfires that burned in Australia from late 2019 to 2020, producing plumes of smoke that reached the stratosphere and circled much of the southern hemisphere.

Those fires sprung up in September 2019 and lasted until March 2020. The fires burned more than 46 million acres (about 72,000 square miles), which is roughly the same area as the entire country of Syria. Thousands of homes and other buildings were lost.

Major fires inject so many sulfates and other particles into the atmosphere that they can disrupt the climate system, push tropical thunderstorms northward from the equator, and potentially influence the periodic warming and cooling of tropical Pacific Ocean waters known as El Nino and La Nina.

According to the study, the COVID-19 lockdowns actually had a slight warming influence on global climate, as a result of clearer skies enabling more heat to reach the earth’s surface. In contrast, the Australian bushfires cooled the Southern Hemisphere because the atmospheric particles reflected some of the incoming solar radiation back to space.

This summer, there have been raging wildfires in the western US and Canada, which have affected air quality in many parts of the nation and have been a serious health hazard. Undoubtedly, these fires are influencing the climate system as well in ways that we are still trying to understand.

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Bushfires, not pandemic lockdowns, had biggest impact on global climate in 2020

Photo, posted January 18, 2020, courtesy of BLM-Idaho via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

People And The Earth’s Increasing Heat | Earth Wise

September 23, 2021 By EarthWise Leave a Comment

A new study by Princeton University and the National Oceanic and Atmospheric Administration had found clear evidence that human activity is the primary cause of the significant increase in heat stored in our planet. In fact, the study found that there is less than a 1% chance that natural variability is the sole cause of the increase.

The researchers looked at data from satellite observations to determine the amount of energy received by the earth and the amount reflected and emitted by the Earth. In a balanced physical system, the amount of incoming energy should equal the amount of outgoing energy. But the earth’s system is not balanced at this point. More energy is coming in than going out, which is driving changes in the climate system. There have been other studies looking at the human influence on the climate, but this new study is the first to examine a 20-year continuous satellite energy balance record to see if natural fluctuations in the climate system or human activities is the primary driver for the significant change in the planet’s energy balance.

The study examined 50 different climate models to look at this energy balance under scenarios where there was no human influence. These include changes in the sun’s output, volcanic eruptions, variations in pollution aerosols, and more.

The results, to no great surprise, are that increasing greenhouse gases over the last twenty years is by far the most important driver for the energy imbalance. This imbalance is what is driving rising temperatures, increasing sea levels, and causing other climate changes.

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Human activities responsible for rapid increase in Earth’s heat

Photo, posted May 6, 2021, courtesy of Marlis Borger via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Short-Lived Climate Forcing Pollutants | Earth Wise

March 9, 2021 By EarthWise Leave a Comment

When talking about the causes of climate warming, it is common practice to bundle together various pollutants and express their effects in terms of “CO2 equivalence.” This involves comparing climate effects of the pollutants on a 100-year timescale. Recent research from the Institute for Advanced Sustainability Studies in Germany points out the problems with this approach.

One of the worst qualities of carbon dioxide is that it accumulates in the atmosphere. Once it gets there, it stays there for anywhere from decades to millennia. On the other hand, short-lived climate forcing pollutants – or SLCPs – stay in the atmosphere for significantly shorter periods. However, some of these are far more effective at trapping heat in the atmosphere. As a result, the atmosphere and climate system react much more quickly to reductions in the emission of these pollutants.

The IASS research study determined that reducing SLCP emissions is an important way to slow near-term climate warming as well as having other positive benefits such as reducing air pollution and improving crop yields. A number of studies indicate that a rapid reduction in SLCP emissions could slow the rate of climate change and reduce the risk of triggering dangerous and potentially irreversible climate tipping points.

Examples of SLCPs are the methane gas emitted from landfills and hydrofluorocarbons that are still widely used as coolants. HFCs only persist in the atmosphere for 15 years but are nearly 4,000 times more effective in trapping heat over a 20-year period.

In order to mitigate the most harmful consequences of climate change, we need to minimize both the near-term climate impacts of SLCPs and the long-term climate impacts of carbon dioxide.

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More Than Just CO2: It’s Time To Tackle Short-Lived Climate-Forcing Pollutants

Photo, posted March 10, 2020, courtesy of Jonathan Cutrer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.