It has emerged that global heating is now accelerating at a rate faster than was previously understood, posing a potentially catastrophic threat to national security and global stability. The stark revelation was presented by research led by James Hansen, the US scientist who first flagged up the greenhouse effect in the 1980s. The new study by Hansen urges that Earth’s climate is more sensitive to human-made changes than scientists realized, with a forecast that the planet will be 1.5°C hotter than pre-industrial levels within this decade and 2°C hotter by 2050.
Hansen said the continued burning of fossil fuels had produced a “dangerous burst of heating” that threatens to make the world “less tolerable to humanity, with greater climate extremes.” If the acceleration in global heating continues, the internationally agreed threshold of 1.5°C above pre-industrial levels, outlined in the Paris Climate Agreement, could be breached decades sooner than previously projected with disastrous consequences for the sea level rise and coastal cities.
This study indicates an imbalance in the incoming energy from the sun and outgoing energy from the Earth, which has “noticeably increased,” nearly doubling over the last decade. With such sensitivity in Earth’s climate and the decrease in cooling pollution produced by shipping, that has caused an acceleration in global heating. Hansen and his colleagues further contend that this trend needs to be reversed if shorelines are to be preserved and coastal cities saved.
Hansen prescribes a global carbon tax and, more provocatively, the sulfur spraying project to deflect heat away from the planet. This latter approach-what scientists call “solar geoengineering”, has proven enormously contentious, not least because of the probable ecological risks involved, besides the chance of a whiplash heating effect if sulfur injections were ever stopped. However, Hansen estimates that with the slow development of carbon-free energies, without pricing carbon emissions, temporary assistance via solar radiation management may become required.
That urgency is underlined by the fact that this year is almost certain to be the hottest ever reliably recorded. A report earlier this year found the carbon budget to limit the world to 1.5°C of heating is nearly exhausted due to the ongoing burning of fossil fuels and deforestation. While scientists agree on the upward trend in global heating, there is debate over whether or not this trend is accelerating.
Michael Mann, a climate scientist at the University of Pennsylvania, counters that Hansen and his fellow authors are “very much out of the mainstream” in finding an acceleration in surface heating. Mann says the rate of global warming has remained remarkably constant over recent decades and that cuts to shipping emissions have only a tiny effect on the climate system. He regards the call for solar geoengineering as being misguided and a “very slippery slope.”
Regardless of these differing opinions, many researchers still agree with Hansen’s supercharged global heating warning, basing their arguments on previous correct predictions of the crisis in the climate. As Rob Jackson, a scientist at Stanford University, says, “Hansen’s contention that the IPCC has underestimated climate sensitivity will likely prove right”. He says nothing has gone down in the use globally, not even coal, and that Hansen’s pessimism is merited since very minimal actions have been taken to stem the use of fossil fuels.
This implication is profound for military strategists and policymakers alike. The accelerating pace of global heating may heighten geopolitical tensions, disrupt global supply chains, and increase the frequency and severity of natural disasters-all sobering challenges to national security. The leaders of the world, military and civilian alike, are supposed to understand strategic threats imposed by this growing crisis and develop plans on all fronts to reduce its impacts.