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1.5 degrees celsius is the new threshold for climate catastrophe

Many of us are still reeling from the UN Panel on Climate Change (IPCC) report published early in October.  It confirms the dire predictions we read in Trajectories of the Earth System in the Anthropocene (Trajectories). The IPCC report reflects the consensus view of top climate scientists in a report that differs from past reports in that it openly rings alarm bells.

A new level of alarm

Hundreds of millions of lives are at stake should the world warm more than 1.5 Celsius above pre-industrial levels. “Nearly all coral reefs will die out, wildfires and heat waves would sweep across the planet annually, and the interplay between drought and flooding and temperature would mean the world’s food supply would become dramatically less secure,” reports David Wallace Wells, New York Magazine writer. Elisabeth Kolbert puts it succinctly, “Perhaps the most important takeaway from the report is that every extra half a degree is world altering.”

This is not news to many climate scientists. The news is that the conservative IPCC is abandoning calm understatement and issuing an alarm.  The main changes from past reports are (1) warming of 1.5 degrees Celsius from pre-industrial levels has now replaced 2 degrees C as the threshold triggering catastrophic climate chaos and (2) our window of time to prevent such warming has shrunk to twelve years.

An effort like no other

Although the report makes clear that it is still possible under the laws of physics to limit global warming to 1.5 degrees C, doing so would require drastic cuts in greenhouse gas emissions at an unprecedented speed. Currently, even with cuts pledged under the Paris Climate Agreement, the world is on track to warm 3 – 4 degrees C.

David Roberts, a Seattle-based climate reporter, warns, “Basically, stopping warming at 1.5 C would involve an immediate, coordinated crash program of re-industrialization, involving every major country in the world. It would be like the US mobilizing for WWII, only across the globe, sustained for the rest of the century. Nothing like this has ever happened. There are currently no indications that any such effort is getting underway, and indeed the US is vigorously moving the other direction.”

12 years is overly optimistic

The IPCC gives us twelve years to cut carbon emissions sufficiently to keep warming from breaching the 1.5 C threshold.  Yet Trajectories shows that we risk triggering an irreversible cascade of amplifying feedback loops that will lead us to Hothouse Earth even before we reach 2C and that may happen as early as 2018.

Even the IPCC engages in wishful thinking, relying on carbon dioxide removal technologies like direct air capture and BCCS to keep warming at 1.5 C, or to remove extra CO2 in scenarios that “overshoot” the 1.5 C goal. There are only a handful of small and experimental sites attempting direct air capture and Bioenergy with Carbon Capture and Sequestration (BCCS) is currently nonexistent and could require the sacrifice of good agricultural and forest land to produce biomass. Relying on BCCS is like relying on science fiction.

It may be even worse than this. Michael Mann, director of the Earth System Science Center at Pennsylvania State says that the IPCC underestimated the amount of warming that has already occurred, “We are closer to the 1.5 and the 2C thresholds than they indicate and our available carbon budget for avoiding those critical thresholds is considerably smaller than they imply.”

We must depend on ordinary people everywhere

Everything depends on whether world governments take this report seriously and begin immediate action commensurate with the threat we face. I have been surfing the internet for comments on the IPCC report, looking for a world leader who is mobilizing her nation’s citizens and economy with the force and speed necessary. I’ve been looking in the wrong place.

Citizens, ordinary people like us, are mobilizing by the thousands around the world. The following reports of demonstrations are taken from the website: Across Australia, people have been delivering copies of the IPCC report to local governments with the message, 1.5 degrees C means zero fossil fuels. On a recent Saturday, 7,000 people in Switzerland marched to their banks, targeting the major funders of fossil fuels. They taped the IPCC report to the banks’ walls. In Bangladesh, women formed a human chain in the Sundarbans, an area threatened by coal. And on the Buriganga River in Dhaka, men demonstrated in their boats, each printed with messages on 1.5C. Just over a month after 150, 000 people came out for the record-breaking March for the Climate in France, over 100,000 were out again pushing the need for climate action.

We must force our governments to act. The actions we force our governments to take in the next few years will determine the future of our climate for hundreds of years, if not millennia.

Bourtai Hargrove is a retired lawyer, a climate change activist, a Socialist and a grandmother.

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