Scientists should study the reflection of sunlight (solar geoengineering).

More than sixty scientists from leading institutions are advocating an accurate study of reflecting sunlight away from Earth to mitigate the effects of climate change.

None of the scientists endorsed the strategy, which is sometimes referred to as “solar geoengineering” and can have significant negative side effects.

Instead, they call for careful and coordinated consideration of the idea before the effects of climate change become so clear and urgent that citizens and governments demand action. They believe this could happen in the next 10-20 years given the current trajectory of carbon dioxide reduction plans.

The scientists wrote in their open letter published on the website website expressly for the purpose of disseminating their scientific point of view. “Natural systems are approaching the thresholds of catastrophic changes with the potential for accelerated climate change and impacts that exceed human adaptive capacity.”

Scientists also emphasize that solar geoengineering is not a solution. Greenhouse gas emissions must be reduced immediately and urgently, as this is the only permanent way to reduce global warming.

Signatories come from prestigious institutions around the world, including Columbia University, Harvard University, MIT, and NASA. However, there is no organization or institution behind the message. It was published as an independent effort by scholars.

The historic Paris Climate Agreement was signed in 2015aiming to keep global warming “well below” 2 degrees Celsius compared to pre-industrial levels, ideally less than 1.5 degrees.

But scientists believe this goal will not be achieved because so many greenhouse gases have already been emitted over the past century and a half, and remain in the atmosphere long after they are released.

“Even with drastic action to reduce greenhouse gas emissions, it is increasingly unlikely that climate warming will remain below 1.5 to 2°C in the near term,” the scientists wrote. “This is because reversing current warming trends would require a significant reduction in atmospheric concentrations of greenhouse gases, which lag significantly behind declines in emissions due to their long atmospheric lifetimes.”

Adding to the concern, air pollution is counteracting global warming. Air pollution particles, also released by human activity, mix in clouds and reflect sunlight away from the Earth for the entire time they remain in the atmosphere.

“It is currently estimated that human-generated aerosols offset about a third of the climate warming caused by greenhouse gases,” the scientists wrote.

But governments are cracking down on air pollution, and as the air becomes cleaner, it will reveal the full amount of global warming caused by human activities.

The scientists warned that “reductions in aerosol emissions in the next few decades will quickly reveal a large but highly uncertain amount of climate warming.”

Meanwhile, experts say technologies for removing carbon dioxide from the atmosphere are still too early to help the world stay below 1.5 degrees of warming.

“There are significant environmental, technical and cost challenges in using carbon dioxide removal (CDR) on the scale required to significantly reduce global warming. While using CDR to stay below 1.5°C may be physically possible, these challenges and the slow response are significant,” the scientists wrote. The climate system makes it unlikely that CDR can be implemented quickly enough or on a sufficient scale to avoid dangerous levels of climate warming in the near term.”

Sunlight can be reflected away from the Earth and can run fast. Scientists said that given the state of our collective global warming, it’s time to take it seriously.

Scientists divide solar geoengineering into three categories:

• stratospheric aerosol injection, SAI, Which involves putting aerosols like sulfur dioxide into the atmosphere to reflect sunlight.
• Brightening Marine Cloud, MCBwhich involves placing sea salt spray in marine low clouds.
• Subtle cloud thinning, CCTwhich involves placing aerosols into cirrus clouds to reduce the amount of infrared radiation that Earth retains.

The first two, SAI and MCB, are commonly referred to as solar radiation modulation, or SRM.

Right now, there isn’t enough research to know exactly how these three technologies will affect the planet. In some cases, the scientists wrote, they may be less harmful if used in certain combinations.

But as the effects of global warming become more severe, “there will be increasing pressure” to use one of these adaptation techniques. That’s why it’s urgent to study them now, the scientists say, as the scientists write that “the current level of knowledge about SRM interventions is insufficient to detect, attribute, or predict their consequences for climate risks.”

The scientists added that peer-reviewed scientific research should include computer simulations, observations, analytical studies and small-scale field experiments. All research must be open and transparent with open access to data.

Use of any of these technologies must be subject to global and international cooperation and decision-making within a framework similar to the Montreal Protocol, which scientists have hailed as a highly successful case of global environmental policy.

In addition, the scientists write that these types of sunlight reflection technologies should not be bought and sold on commercial markets as a means of offsetting carbon emissions.

“The state of scientific knowledge about SRM is currently insufficient to include it as part of a climate credit scheme or other commercial proposition, as some have begun to suggest. Even for stratospheric aerosol injection (the most well-understood SRM approach), the amount of cooling achieved by injecting a given mass of The materials and how SAI will affect the climate system remains highly uncertain.”

“Even with an improved understanding of these effects, since SRM does not address the cause of climate change, nor all the effects of increased greenhouse gas concentrations, it is likely that it would not be a suitable candidate for an open market system of credits and independent actors.”