World emissions added heat “equivalent to 1.7 billion atomic bombs to the ocean,” a stark reminder of what’s at stake, according to a new briefing amid the ongoing UN Ocean Conference (UNOC) in Nice centered around conservation and sustainable use of oceans and marine resources.
Scientists say the “world added the energy equivalent of nearly two billion atom bombs such as “Little Boy” to the ocean since the Paris Agreement was signed in 2015. The ocean heat content in 2025 (to a depth of 2000m) was about 104 zettajoules more than in 2015, equivalent to about 1.7 billion atom bombs (about five bombs per second)”
Collated by research consultancy Climate Trends, the data-backed snapshot of dramatic changes happening beneath the surface —record sea temperatures, shrinking sea ice, and mass coral bleaching—from publicly available data, has been reviewed by scientists.
“Global warming over the last 10 years equates to about 1.7 billion atomic bomb explosions, or if we divide this by the number of seconds in 10 years, it’s equivalent to about 5 atomic explosions worth of energy every single second,” according to Dr Alex Sen Gupta from University of New South Wales, Sydney
Climate change impacts on the ocean since 2015 include global sea ice hitting an all-time low this year, sea surface temperatures in 2024 smashing previous records, 84% of coral reef areas bleached in the biggest coral bleaching event ever.
Gupta says “an extra 104 zettajoules entering and warming the climate system—that’s 104 thousand, million, million, million Joules of energy” have been measured over the past decade
“Clearly this is having an effect on the ocean –it’s causing sea level to rise, our ice systems to melt, and our atmosphere and oceans to warm. The last of these means increasing numbers of marine heatwaves, with the devastation that they bring. All this energy comes from humans putting more and more greenhouse gases into the atmosphere. Clearly this needs to stop,” he adds
It has been 10 years since the Paris Agreement. World leaders are currently in France along with NGOs, leaders of island states and scientists to dwell upon ocean action.
