How Geoengineering Technologies Can Combat Heatwave Impacts

Temperatures have steadily increased since global records began in 1850. According to NOAA, the rate of warming since 1982 is more than three times as fast: 0.36°F (0.20°C) per decade. 2023 was the warmest year since global records began in 1850 by a wide margin, and the past decade, between 2014 and 2023, was also the warmest year in the historical record.

NOAA’s record shows that the Earth has warmed roughly 2 degrees Fahrenheit (1 degree Celsius) since the pre-industrial period. This extra heat is leading to record regional and seasonal temperatures, receding snow cover and sea ice, intensifying heavy rainfall, and shifting the habitat ranges of animal and plant species (shrinking them or entirely shifting them to new geographic locations because of the changing climates).

Dangers of extreme heat

North America, Europe, and China experienced extreme heatwaves in July 2023, which the World Weather Attribution attributed to climate change. The Guardian reports that in April this year, Southeast Asian countries were also gripped by intense heatwaves, with temperatures reaching 46°C in the Philippines and 44°C in Myanmar. According to Harvard T.H. Cahn School of Public Health, just two days or more of 90°F or higher (32.22 °C) could lead to severe health conditions such as dehydration, heat exhaustion, or heat stroke and worsen chronic conditions like asthma, migraine, kidney diseases, hypertension, and cardiovascular diseases. We’re warm-blooded,” said Aaron Berstein of the Harvard T.H. Chan School of Public Health. “Our whole body is designed to operate within a narrow range of temperatures.”

The impact of extreme heat is not evenly distributed. Those most affected are often people with low incomes and communities of colour, who are more likely to live in heat islands—hotter areas due to the high concentration of heat-absorbing roads and buildings and the lack of heat-reducing tree cover and green space. These groups may also lack access to air conditioning, exacerbating the health risks.

Solutions to climate change

There are myriad solutions, from the governance to the individual level, to combat intense heat or rising temperatures due to climate change.

If you have brought a reusable bag to the grocery, use a reusable mug to buy coffee or a water bottle instead of a disposable one, practice recycling, eat less meat, use public transport, walk or bike to work, switch to electric cars, planting trees, saving energy at home then these are individual actions that can help mitigate climate change. Experts do not think individual actions will be enough to tackle climate change, but they agree that governments and businesses should also do their part.

Government policies to tackle the climate crisis could include implementing carbon taxes to minimise GHG emissions and the cause of climate change. However, additional taxes on energy could increase the price of energy for businesses and affect lower-income households, as companies tend to pass these added costs on to consumers. Sweden was one of the first countries to implement a national carbon tax in 1991 and has successfully reduced GHG emissions by 27%.

Governments can also pass clean energy standards legislation, encouraging utility companies to obtain their energy from clean or renewable sources. In 1999, Texas instituted a clean energy standard to source ten thousand megawatts of electricity—enough energy to power a thousand homes for a year—from renewable energy by 2025. The standard has spurred growth in renewable energy in the state, with renewables now accounting for 25% of all the electricity it generates.

Extreme weather events like heatwaves, droughts, and floods are becoming more frequent and severe. Governments can address these natural hazards by instituting climate adaptation policies to bolster resilience and reduce vulnerabilities.

Climate adaptation policies can range from building climate-resilient roads, bridges, and airports to withstand extreme weather conditions to creating evacuation or relocation plans to implementing policies that minimise the financial risk posed by climate change. Examples of policies to prepare for climate-related economic shocks include mandating that everyone has access to flood and fire insurance and that financial institutions like banks, companies, and insurers disclose whether and to what extent climate change has the potential to affect their investments.

Governments can also support or subsidise the development of geoengineering technologies that aim to reduce or counteract the impacts of climate change. According to research, Geoengineering strategies can be broadly classified into two types of intervention: solar radiation management (SRM) and carbon dioxide removal (CDR). Geoengineering Monitor provides examples of CDR and SRM technologies that could be implemented at a large scale to combat climate change.

Cloud brightening is an example of a solar radiation management technique. It aims to make clouds brighter, reflecting a fraction of incoming sunlight into space to offset rising temperatures.

Elevated GHG atmospheric concentrations have increased the difference between the amount of the sun’s energy absorbed in the Earth’s atmosphere and the amount reflected into space. This imbalance is called radiative forcing. According to NOAA, the Earth’s radiative forcing has increased from Earth, and the amount of energy radiated back to space has risen from 1.798 W/m2 in 1979 to 3.398 W/m2 in 2022, increasing global temperatures.

SRM will increase the Earth’s ability to deflect sunlight by raising the albedo of the atmosphere or the Earth’s surfaces, thereby reducing most global warming effects from rising GHG emissions.

Scientists from the University of Washinton tested a marine cloud brightening intervention on 8 April 2024. The Seattle Times reports that scientists aboard a World War II-era deck blasted a plume of saline spray off the coast of Alameda, California

The scientist developed the Cloud-Aerosol Research Instrument, also known as CARI. It pumps compressed air at hundreds of pounds per square inch through a nozzle full of a salty mix similar to seawater, releasing a fine mist that travels hundreds of feet through the air. The goal is to improve clouds’ ability to reflect sunlight toward space and help cool the Earth.

Marine cloud brightening is not a “silver bullet” for climate change. Scientists have made it clear: the priority remains to reduce carbon dioxide emissions and tackle the root causes of climate change head-on. However, in a world where every bit helps, exploring innovative solutions like cloud brightening offers a glimmer of hope and a potential tool in our climate action toolkit (Harris, 2024).