Scientists will “cover the sun” from Spring 2019 to save the Earth

A team of scientists at Harvard University is planning to tackle climate change through geoengineering, by blocking out the sun. The concept has been around for decades, but this is the first time researchers will actually block out the sun to save the Earth.

Scientists will "cover the Sun" from Spring 2019 to save the Earth.

The project, called the Stratospheric Controlled Perturbation Experiment (SCoPEx), will use $3 million to test the model by launching a balloon that can travel 20 kilometers (12 miles) above the southwestern United States. Once in place, the balloon will release tiny calcium carbonate particles. The plan is to launch as early as spring 2019.

The experiment was based on research into the effects of large volcanic eruptions on the planet's temperature. In 1991, Mount Pinatubo in the Philippines erupted, releasing 20 million tons of sulfur dioxide into the stratosphere. The sulfur dioxide created a blanket around the Earth's stratosphere, cooling the entire planet by 0.5°C for about a year and a half.

As scientists, government agencies around the world, and environmental groups become increasingly concerned about reducing greenhouse gas emissions and curbing climate change, the idea of ​​geoengineering as a solution is becoming more acceptable. The ultimate goal is to reduce global warming, which can be done by reducing greenhouse gas emissions, absorbing CO₂from the atmosphere or limit the sunlight reaching the earth's surface.

The first two approaches are actively discussed and implemented to varying degrees. The recent commitment by G20 members (the United States being the sole abstainer) is to act to address the source of the problem by reducing greenhouse gas emissions. CO2 Absorption₂from the atmosphere and trapping it in the Earth's crust is called CO sequestration.₂, have been deployed. For example, Royal Dutch Shell has worked with the Canadian and Australian governments to build large carbon sequestration facilities.

The third method, blocking sunlight, has been controversial in the scientific community for decades. The controversy lies in the fact that no one is able to predict the consequences of blocking some of the Sun's light.

Reducing global temperatures is clear and on track, however, questions remain about the impact this will have on rainfall, the ozone layer and global crop yields.

A team of scientists at Harvard University will develop a solution to release calcium carbonate into the stratosphere.

That’s exactly why the Harvard team plans to spray tiny particles of chalk (calcium carbonate) into the stratosphere in a controlled experiment. Computer models can only go so far in predicting the effects of this technique. With funding in part from Microsoft co-founder Bill Gates, the Harvard team will begin answering the remaining questions as early as spring 2019.

Although the potential negative impacts are not fully characterized, the possibility of controlling the Earth’s temperature by injecting small particles into the stratosphere is an attractive solution because of the cost of implementation. A recent report by the Intergovernmental Panel on Climate Change (IPCC) estimated that continuously releasing particles into the stratosphere could offset 1.5°C of warming at a cost of only $1-$10 billion per year.

When these costs are compared to reducing fossil fuel use or sequestering carbon globally, the approach becomes very attractive. Therefore, scientists, government agencies, and independent funders of the technology must balance the effectiveness and cost-effectiveness of the approach with the potential risks to global crops, weather conditions, and droughts. Ultimately, the only way to fully characterize the risks is through real-world experiments, like the Harvard team is embarking on.