Surplus heat is the new climate challenge

The World Meteorological Organisation’s (WMO) latest State of Climate Report confirms the agency’s findings over the last 10 years. The decade that ended last year was the hottest on record. The carbon dioxide in the atmosphere is about 50 per cent higher than pre-industrial levels. In 2025, even as renewable energy edged out coal as the leading source of electricity, global emissions reached record levels. Even though clean power has registered an appreciable increase, it’s nowhere close to keeping pace with the world’s appetite for energy. All this means that the concentration of carbon dioxide reached its highest level in the last 2 million years, and methane and nitrous oxide in at least the last 800,000 years. In itself, these are sobering figures. The WMO report adds another worrying dimension – the record levels of GHG have upset the Earth’s energy equilibrium. Ideally, the amount of radiation entering the planet and the amount of it leaving it should be roughly similar. But a heat surplus has accumulated in the past six decades. That means that even if GHG emissions were to completely stop anytime soon, the planet will continue to warm.

Since water can store large amounts of heat, the seas and oceans have become the main repositories of the extra energy trapped by GHGs. The total effects on oceans are not fully understood. But some of them are apparent. As the authors of the WMO report point out, warmer oceans create conditions for stronger tropical storms. At the same time, melting ice is pushing up sea levels and weakening the planet’s ability to reflect solar radiation back into space, aggravating the energy imbalance in the process.

Incremental changes are unlikely to change the trajectory of extreme weather events. Therefore, even as they devote resources towards green methods of production, planners must find ways to make infrastructure more resilient, invest more in early warning systems and shield the vulnerable. The energy imbalance could unfold over decades. Policies must, therefore, be stable enough to guide investments and research over long time-scales. The most important message for governments and the political class worldwide is this: They need to find the resolve and creativity to insulate climate policies from short-term politics.