IPCC report fails to address ‘known unknowns’, climate groups claim

9 Oct 2018

Image: ©Alexander/Stock.adobe.com

In the wake of the truly scary IPCC climate report, some climate scientists have claimed that it actually didn’t go far enough.

The release of the Intergovernmental Panel on Climate Change (IPCC) report yesterday (8 October) was a slap in the face to policymakers across the globe, warning them that if drastic action isn’t taken immediately, millions of lives will be at stake.

The document with 91 authors and 42,000 expert comments laid out the future of our planet should it become two degrees Celsius warmer versus 1.5, and what we need to do to achieve a reduction in temperature.

However, according to The Guardian, some climate scientists and groups have criticised it, not for its base claim, but the fact that it hasn’t gone far enough. The key problem, they said, is that it does not address the ‘known unknowns’, which are unforeseen tipping points that could have even more drastic effects in years to come.

For example, some of the issues the report didn’t describe in depth include the issue of water vapour trapping heat in Earth’s atmosphere, the loss of polar ice and the major migration of tropical clouds into the polar regions.

Dreaded feedback loops could also occur, where melting sea ice reveals darker, heat-absorbing water that triggers further warming in a continuous cycle.

The danger of feedback loops

The Grantham Institute’s Bob Ward highlighted one noticeable oversight. “The IPCC summary for policymakers only mentions the west Antarctica and Greenland tipping points, which we may already have reached,” he said.

“The underlying report suggests that the other tipping points are too poorly understood, or not likely to be triggered until higher amounts of warming – but, given their consequences, one would expect a more risk-based approach. That is, you don’t ignore them until you know them to be impossible.”

Further damage could be caused by melting permafrost, believed to contain vast amounts of the highly polluting gas methane, considerably more destructive to our atmosphere than CO2.

This too, some scientists claim, is another unknown that has not been examined in great enough detail, along with the effects of climate change on the planet’s carbon sinks. These areas, particularly forests, may lose their ability to absorb carbon if their soils are dried out due to rising temperatures.

One of those scientists is 1995 Nobel Prize in Chemistry laureate Mario Molina, who said: “Even with its description of the increasing impacts that lie ahead, the IPCC understates a key risk: that self-reinforcing feedback loops could push the climate system into chaos before we have time to tame our energy system and the other sources of climate pollution.”

Colm Gorey was a senior journalist with Silicon Republic