side effects

Cloud brightening

June 17, 2024 By EarthWise Leave a Comment

Solar geoengineering is a type of climate intervention: deliberate actions designed to affect the climate. There are several ways to try to reduce the amount of sunlight reaching the surface of the earth and all of them are controversial. Perhaps the least controversial approach is cloud brightening.

The idea is based on something called the Twomey effect, which is that large numbers of small droplets in the atmosphere reflect more sunlight than small numbers of large droplets. Spraying vast quantities of minuscule aerosols into the sky, thereby forming many small droplets, could change the reflective properties of clouds. If clouds are more reflective, then less sunlight reaches the surface, and the temperature goes down.

This form of geoengineering is thought to be less risky because it can be performed on a localized basis and can use relatively benign materials such as sea salt.

In early April, scientists from the University of Washington started testing a device that sprays tiny sea-salt particles into the air from the deck of a decommissioned aircraft carrier in Alameda, California. The test was simply to see whether the machine propelled a mist of suitable size.

Within two weeks, Alameda officials ordered a stop to the experiment, citing potential health and environmental risks. After a month-long investigation, Alameda ruled that the experiment does not generate a measurable risk to health, wildlife, or the environment.

But before more ambitious experiments take place, there are potential side effects of cloud brightening that need to be studied. It may turn out to be a useful tool in fighting global warming, but in any case, such technology should not be viewed as a substitute for moving away from fossil fuels.

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A Test of Cloud-Brightening Machines Poses No Health Risk, Officials Say

Photo, posted September 8, 2011, courtesy of Justin Ladia via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Geoengineering Research Plan | Earth Wise

July 22, 2022 By EarthWise Leave a Comment

The 2022 federal appropriations act, signed into law in March, directed the Office of Science and Technology Policy to develop a cross-agency group to coordinate research on climate interventions, in partnership with NASA, the National Oceanic and Atmospheric Administration, and the Department of Energy.

The group is tasked with creating a research framework to “provide guidance on transparency, engagement, and risk management for publicly funded work on solar geoengineering research.” The group is supposed to develop a five-year plan that will define research goals for the field, assess the potential hazards of climate interventions, and evaluate the level of federal funding required to carry out the work.

This marks the first federally coordinated effort of this kind and is especially significant because it contributes to the perception that geoengineering is an appropriate and important area of research as the climate continues to warm.

It is an understatement to say that such research is controversial. Geoengineering has often been a taboo topic among scientists. There are significant questions about potential environmental side effects and concerns that the impact of any such efforts would be felt unevenly in different parts of the world. There are challenging questions about global governance , including who should be able to make decisions about any potential deployment of climate interventions and what the goals of such interventions should be.

These are momentous issues to grapple with, but as the threat of climate change grows and nations continue to fail to make rapid progress on emissions, researchers, universities, and nations are increasingly motivated to seriously explore the potential effects of geoengineering approaches. We can’t hide from the fact that these issues are going to be explored.

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The US government is developing a solar geoengineering research plan

Photo, posted June 28, 2013, courtesy of Fernando Aramburu 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.

Should New York Build A Storm Surge Barrier?

December 6, 2019 By EarthWise Leave a Comment

In 2012, Superstorm Sandy’s storm surge combined with a high tide and buried lower Manhattan under 13 feet of water. Across all five boroughs, subways, highways, and parking garages flooded and homes and businesses were destroyed. Sandy caused nearly $20 billion in damages in New York City alone and more than 50 people died.

Ever since that disaster took place, there have been discussions about building storm surge barriers to protect the city from future storms. Columbia University’s Sabin Center recently hosted an event to discuss the feasibility of building such barriers.

A study by the U.S. Army Corps of Engineers called the NY and NJ Harbor and Tributaries Focus Area Feasibility Study (HATS, for short) evaluates five options for coastal protection, which range in scope and price.

The most extensive option would involve constructing six miles of storm surge gates along with 26 miles of floodwalls, levees, and buried seawalls. This option would cost $62 billion but could theoretically save $131 billion in damages and protect 95% of the study area.

The study also considers the side effects of building storm surge barriers. These include environmental impacts such as effects on fish and wildlife, water quality, noise and vibrations, and changes in water flow. While these effects can be quite serious and there is opposition from many quarters related to environmental impacts, others point out that there is really no other credible defense against storm surge. The debate over whether or not to build storm surge barriers could easily last for many more years.

In the bigger picture, storm surge barriers do nothing to protect against rain-driven flooding, sea level rise, and tidal floods which continue to increase.

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Should New York Build a Storm Surge Barrier?

Photo, posted October 30, 2012, courtesy of Pamela Andrade via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.