warming trend

El Niño Will Likely Return | Earth Wise

June 21, 2023 By EarthWise Leave a Comment

El Niño, a weather phenomenon triggered by warm waters in the eastern Pacific, is likely to return this year, according to the World Meteorological Organization. The Pacific has been in the cooler La Niña phase for the past 3 years, which is unusual, but that appears to be coming to a close. According to the WMO, there is an 80% chance that the Pacific will shift to the El Niño phase before fall.

Record hot years typically coincide with El Niño, which adds to the ongoing warming trend in the climate. There is not yet a clear picture of how strong the forthcoming El Niño event will be or how long it might last, but even a mild El Niño could affect precipitation and temperature patterns around the world.

The hottest year on record, 2016, occurred during a particularly strong El Niño. Experts expect that 2024 is likely to see soaring temperatures again. El Niño generally leads to drier conditions in Australia, Indonesia, and southern Asia, but greater amounts of rainfall in South America, the U.S., and parts of Africa. Despite the presence of a cooling La Niña for the past three years, the last eight years have been the hottest on record.

El Niño and La Niña form an intermittent cycle known as the El Niño Southern Oscillation, or ENSO, that is highly influential in shaping the year-to-year variations in weather conditions around the world. ENSO is a natural phenomenon and scientists are still trying to understand how human-caused climate change might be impacting the behavior and dynamics of the cycle.

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‘A New Spike’ in Global Temperatures in the Forecast

Photo, posted October 11, 2015, courtesy of Harshil Shah via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Even The Deep Sea Is Warming | Earth Wise

November 17, 2020 By EarthWise Leave a Comment

Approximately 75% of the area covered by ocean is deep, dark, and cold. This is known as the deep sea. But even in these remote regions of the planet things are heating up.

According to a new study published in the journal Geophysical Research Letters, researchers analyzed a decade of hourly temperature readings at four depths in the Atlantic Ocean’s Argentine Basin, off the coast of Uruguay. The research team selected recording depths that would best represent the average depth of the ocean, which is just over 12,000 feet.

The researchers found that deep sea temperatures fluctuate more than was previously known. They also detected a warming trend at the bottom of the ocean. In fact, all recordings indicated a warming trend of 0.02 to 0.04 degrees Celsius per decade between 2009 and 2019. This is a significant warming trend in the deep sea because temperature fluctuations are typically measured in thousandths of a degree.

Researchers say this increase is consistent with warming trends in the shallow ocean associated with anthropogenic climate change. However, they say more research is needed to better understand what is driving the warming temperatures in the deep sea.

A better understanding of what is driving these changes could have far-reaching implications. Since oceans absorb a significant amount of the world’s heat, learning about the oceans’ temperature trends could help researchers better understand temperature fluctuations in the atmosphere as well.

The researchers hope their findings will demonstrate the need to survey deep ocean temperatures annually in order to better identify the long-term trends.

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The deep sea is slowly warming

Photo, posted July 1, 2018, courtesy of NOAA Ocean Exploration and Research via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And The South Pole | Earth Wise

August 10, 2020 By EarthWise Leave a Comment

According to a study led by researchers at Ohio University, the South Pole has warmed more than three times the global average over the past 30 years. While the warming was driven by natural tropic climate variability, the researchers argue that rising greenhouse gas emissions likely intensified the warming.

The climate in the antarctic has some of the largest ranges in temperature during the year. Some regions, like most of West Antarctica and the Antarctic Peninsula, experienced warming during the late 20th century. But the South Pole, which is located in the remote and high-altitude interior of the continent, actually cooled until the 1980s. The South Pole, as the study highlights, has warmed substantially ever since.

For the study, which was recently published in the journal Nature Climate Change, the researchers analyzed climate models and weather station data at the South Pole. They found that, between 1989 and 2018, the South Pole had warmed by 1.8 degrees Celsius. This warming trend of 0.6 degrees Celsius per decade is three times the global average.

According to the study, the robust warming of the Antarctic interior has been mainly driven by the tropics. Warm ocean temperatures in the western tropical Pacific Ocean have altered the winds in the South Atlantic, increasing the delivery of warm air to the South Pole. These atmospheric changes are an important part of what’s driving the climate anomalies in the region.

But the researchers argue that the warming trends are unlikely a result of natural climate change alone. The effects of anthropogenic – or human-caused – climate change in addition to the natural changes have combined to make this one of the strongest warming trends globally.

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Extreme warming of the South Pole

Photo, posted February 7, 2011, courtesy of Eli Duke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Side Effects Of Geoengineering | Earth Wise

July 20, 2020 By EarthWise Leave a Comment

As the world struggles to reduce the greenhouse gas emissions that are warming the global climate, some researchers are exploring proposals to deliberately engineer climate changes to counteract the warming trend. One of the most widely discussed approaches is to shade the Earth from a portion of the sun’s heat by injecting the stratosphere with reflective aerosol particles. Proponents of this idea point out that volcanoes do essentially the same thing, although generally for only a limited amount of time. Particularly large eruptions, such as the Krakatowa eruption of 1883, wreaked havoc with weather around the world for an entire year.

Schemes to launch reflective aerosols – using planes, balloons, and even blimps – appear to be quite feasible from the standpoint of physically accomplishing them. But this says nothing about the political, ethical, and societal issues involved. The point is that such an approach could indeed lower global temperatures and thereby potentially offset the warming effects of greenhouse gases.

A study by scientists at MIT looked at what other effects such a solar geoengineering project might have on the climate. Their modeling concluded that it would significantly change storm tracks in the middle and high latitudes. These tracks give rise to cyclones, hurricanes, and many more ordinary weather phenomena.

According to the study, the northern hemisphere would have weakened storm tracks, leading to less powerful winter storms, but also stagnant conditions in summer and less wind to clear away air pollution. In the southern hemisphere, there would be more powerful storm tracks.

Aside from turning the world’s weather patterns inside out, solar geoengineering would do nothing to address the serious issue of ocean acidification caused by increasing carbon dioxide levels.

As many have pointed out, playing the geoengineering game would have many unintended consequences.

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Study: Reflecting sunlight to cool the planet will cause other global changes

Photo courtesy of MIT.

Earth Wise is a production of WAMC Northeast Public Radio.

Why The Arctic Is Warming So Fast | Earth Wise

April 7, 2020 By EarthWise Leave a Comment

The Arctic has been warming at the fastest rate of any place on Earth. There have long been observations of amplification of Arctic warming, meaning that its temperature increases have been well above what would be expected from the global temperature rise.

Many climate models have attributed this warming to the melting of sea ice. As the bright white ice disappears for longer periods of the year, the dark surface waters that are exposed absorb sunlight rather than reflecting it back into space the way the ice does. This is known as the ice-albedo feedback. But it does not entirely explain the amount of warming in the Arctic.

Researchers at the Scripps Institution of Oceanography have developed a new theory that helps to explain what is going on.

In the areas of the Arctic Ocean where there is sea ice, the water is actually warmer at depth and colder near the surface. The deeper waters are fed by the relatively warm Pacific and Atlantic Oceans while the surface water is cooled by the ice. The increasing temperature difference between surface and deeper water causes a greater upward flow of heat. This was first observed in research cruises that revealed evidence that the Arctic Ocean water was becoming more turbulent over time.

According to computer modeling, this phenomenon is responsible for about 20% of the amplification of global warming that occurs in the Arctic.

There are multiple ongoing studies looking at the Arctic warming trend. Other factors that have contributed over time are the presence of chlorfluorocarbons in the atmosphere. That contribution is waning since the use of CFCs has been phasing out over time.

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Researchers Find New Reason Why Arctic is Warming So Fast

Photo, posted April 19, 2017, courtesy of Markus Trienke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.