CAN WE STOP EARTH HEATING UP?

In 2021, Earth hits a bleak milestone. The concentration of carbon dioxide (CO₂) in the atmosphere will hit 150 per cent of its value in preindustrial times. That excess will be the consequence of human activities, the direct cause of the current climate emergency. If global temperatures are to remain no more than 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial levels, according to the United Nations’ Intergovernmental Panel on Climate Change (IPCC), the world needs to decrease net emissions of CO₂ to zero by 2050.

But even this won’t put a sudden brake on the temperature rise, because it takes time for CO₂ reductions to take effect. The negative impacts of global warming will continue for decades to come, but is there anything else we can do to help bring temperatures back down to normal sooner?

A research group at Harvard thinks it might be possible to achieve a temporary reduction in global temperatures by making small tweaks to the composition of