Since 1850, the planet has heated by about 1.2 C, with the 2023 warming reaching a record-breaking 1.45 C.
In the last 50 years alone, this has caused society roughly $4 trillion in losses. The health impacts of climate change have been tragic, profound and multifaceted, causing irreversible harm to people’s lives. High-intensity climate disasters contribute to the spread of disease and significantly impact mental health. Air pollution from fossil fuels alone causes more than 5 million premature deaths annually.
Climate change is emerging as a significant driver of forced migrations, with more than 3.6 billion people living in vulnerable areas and an average of 21.5 million people displaced annually since 2008. By 2050, climate change could force 44.2 million to 216 million people to move within their countries — even within one as prosperous as the United States.
More heating during the next 50 years could lead to staggering losses of $178 trillion, millions of premature deaths, new epidemics, forced migrations and the global implosion of vital food systems.
But there’s a new way to look at the climate problem. On May 15, at the Vatican, we will propose a strategy for surviving the crisis and thriving in its aftermath called MAST: mitigation, adaptation and social transformation. We will present MAST to our colleagues in the Pontifical Academies, Pope Francis and a transdisciplinary confluence of scientists, mayors, governors, researchers, NGOs and policymakers. The governors of California, Massachusetts and New York have committed to representing the United States
MAST aims to achieve the following:
Mitigation to bend the emissions curve involves phasing out fossil fuels and drastically reducing short-lived climate pollutants (methane, hydrofluorocarbons, ozone precursors and black carbon soot) to reduce warming quickly. Over the next 20 years, we aim to lower the climate by as much as 0.5 C. In addition, to stabilize the climate around 1.5 C, we need to remove as much as 300 billion tons of carbon dioxide from the atmosphere. We already see it can be done.
According to the most recent National Climate Assessment, “annual U.S. greenhouse gas emissions fell 12 percent between 2005 and 2019,” largely due to “changes in electricity generation.” A drop in coal use and increases in natural gas and renewables led “to a 40 percent drop in emissions from the electricity sector.”
Adaptation will be necessary to cope with unavoidable planetary heating. We prioritize green energy, sustainable food, clean water, and air security for all, coordinating local and global efforts and focusing on regional climate hotspots. In our approach, adaptation must be given the same priority as mitigation. The good news is that $1 trillion spent on adaptation yields a return of $7 trillion in benefits.
Societal Transformation must underlie a rebound to a sustainable way of living. It involves a fundamental shift in behavior, governance and socioeconomic systems. It entails promoting ecological conversion and sustainable living. Education must lead the way. Again, there is good news: Youth worldwide demand that we act on climate change now.
The urgency posed by the planetary warming crossing the 1.5°C (2.7°F) threshold in about six years calls for immediate, concerted global action akin to the successful response to the Antarctic Ozone Hole in the 1980s, which led to the Montreal Protocol and the eventual ban on chlorofluorocarbons.
We no longer have the luxury of relying solely on emissions mitigation. We need to build climate resilience, which involves bending the emissions curve of all heat-trapping pollutants and removing carbon from the atmosphere while urgently adapting to ongoing climate changes. This requires behavioral changes, educational innovation, sustainable consumption and a significant effort to aid the poorest in the world as we adapt to climate change emergencies.
Climate justice is justice for all. A sobering look at the new data reveals stark ethical issues arising from climate warming. Approximately 4 billion people, accounting for 50 percent of the global population, are responsible for 89 percent of emissions, while the other half contribute less than 12 percent but suffer 75 percent of the losses from climate impacts. At a more granular level, the top one billion emit as much as 50 percent to 60 percent of the total emissions.
Today’s climate crises threaten children and rob future generations’ right to flourish fully within nature. It should come as a reassurance that the remedies outlined in MAST are readily available.
Marcelo Suárez-Orozco is chancellor of the University of Massachusetts Boston & the UCLA Wasserman Dean Emeritus. Veerabhadran (Ram) Ramanathan is a distinguished research professor at the University of California at San Diego and an adjunct professor at Cornell University.