Top scientists at Nasa have noted that the current pace of global warming is unprecedented by any warming period in the last millennia, making it unlikely that temperature increases will remain under the 1.5 Celsius limit set at the Paris climate accord. Average global temperatures have peaked at 1.38 Celsius above temperatures recorded in the 19th century. Since last October, every month has set a new record mark for heat, with this July marking the hottest month since the start of records in 1880. Nasa has pointed out the fact that records go back much further when they include analysis of ice cores and sediments, and with this data in mind, they show how today’s warming trend goes above and beyond anything in the last 1000 years.
Gavin Schmidt, director of Nasa’s Goddard Institute for Space Studies, points out that “In the last 30 years we’ve really moved into exceptional territory. It’s unprecedented in 1,000 years. There’s no period that has the trend seen in the 20th century in terms of the inclination (of temperatures).” Schmidt also points out that 2014 and 2015 were both the warmest years on record at the time, and that there is a 99 percent chance that 2016 will be as well. Schmidt also adds “Maintaining temperatures below the 1.5C guardrail requires significant and very rapid cuts in carbon dioxide emissions or coordinated geo-engineering. That is very unlikely. We are not even yet making emissions cuts commensurate with keeping warming below 2C.”
This bleak prediction from one of the world’s top climate scientists comes just months after the 1.5 Celsius target was adopted at last December’s UN summit. The 1.5 Celsius target was set at the behest of island nations whose land would be flooded by rising seas if that target is not met. Other research by the Intergovernmental Panel on Climate Change showed that just 5 more years of current levels of carbon emissions would virtually destroy the possibility of keeping temperatures under the 1.5 Celsius target.
Using temperature reconstructions, Nasa estimates that the past century of temperature increases rose at a rate around 10 times faster than the typical rate of increase coming out of an ice age. With the carbon dioxide that is already emitted and lingering in the atmosphere projected to raise sea levels by three feet by the end of century, and 70 feet over the following centuries, these numbers point to an immediacy not universally accepted in relation to climate change.