by Drew Shindell, Nicholas Distinguished Professor of Earth Science


Fifty years ago, scientists were aware of the warming effect of carbon dioxide on our atmosphere but had almost no satellite data to aid their observations. This made it hard to understand the Earth as a whole system and grasp how intricately climate was tied to other elements within the system.

Since then, there’s been a fundamental revolution in observational technologies and computing power. These tools enable us to observe much more clearly and comprehensively the impacts of climate change, identify what’s driving it, and project its future impacts. We now know what actions are needed to avoid the worst impacts. We know the deadlines for completing those actions. And we know that our actions must be aimed not only at reducing emissions but also at reducing climate change’s adverse impacts on human health and the economy.

These are huge advancements.

Now, the challenge is, how do we use this knowledge to inspire – or push – our political and corporate leaders to act before it’s too late? A big part of our success, I believe, will depend on our ability to resolve misaligned incentives.

The most powerful incentives for an individual actor – a carmaker, for example, or a U.S. president running for re-election – don’t necessarily align with societal incentives. This is because the benefits of reducing emissions are deferred into the future, beyond the current election cycle or the next quarterly earnings report, and mostly accrue to others.

We need to give these actors reasons to act that are more immediate and tangible and will have currency among their investors or constituencies.

A climate policy approach that emphasizes the economic and human health co-benefits of reducing emissions could guide governments down the right path and spur the speed of emissions reductions.

My own research shows that as many as 153 million premature deaths linked to air pollution could be avoided this century if governments speed up the timetable for reducing fossil fuel emissions, rather than postponing the biggest emissions cuts until later, as some have proposed. Cutting emissions sooner than later would also boost global food security and help farmers by reducing crop losses linked to rising temperatures, increased droughts, air pollution and flooding. Additionally, it would reduce biodiversity losses and slow amplifying climate feedbacks such as snow-and-ice albedo. Many of these benefits happen very quickly as well.

There would be economic gains, too, to help defray the costs incurred by taking swift action. One example of this is how emissions and energy costs have been reduced, and investments in energy efficiency and renewable energy have increased, in 10 northeastern states, through the Regional Greenhouse Gas Initiative (RGGI), the nation’s first mandatory, market-based cap-and-capture program to cut emissions from the energy sector. Another is our ongoing work quantifying increased labor productivity and reduced health care spending stemming from climate change mitigation.

The 2018 Intergovernmental Panel on Climate Change Special Report, which I was a coordinating lead author of, conclusively showed that targeting immediate reductions in emissions is the most beneficial path we can take toward achieving the goal of limiting global temperature rise to 1.5°C. Governments could, conceivably, delay reducing these pollutants for decades and still achieve that goal. But why would they want to if there are all these advantages to be gained by following this path, instead?