In the last two decades, we have been confronted with an avalanche of climate change reports.  Some use more reliable data than others.  Some employ hysterical projections of catastrophe. Almost all trigger opposing criticisms from those with doubts about the pace and consequences of global warming and from those who feel the reports understate the urgency for radical action.

In 2015, 184 parties agreed to the Paris Climate Accord.  Its long-term goal is to keep the increase in global average temperature to well below 2°C above pre-industrial levels. The intention is to limit the increase to 1.5°C, since this would substantially reduce the risks and effects of climate change.  The U.S. and Syria refused to agree, although the U.S. has for years undertaken aggressive steps to mitigate greenhouse gases from power production and tailpipe emissions.

In September 2018, 13 U.S. agencies produced their second volume of the National Climate Assessment (NCA Vol 2).  The NCA Vol 2 report is generally in agreement with the climate report that preceded the Paris Accord. Some regard it as flawed, since it chose extreme scenarios as a foundation for predictions of rampant wildfires and hurricanes.

NCA Vol. 2 claims that unless aggressive steps are taken to rein in carbon dioxide, the U.S. will suffer a 10% reduction in GDP by end of this century.

In December 2018, representatives of 200 nations gathered in Katowice, Poland to develop the Paris Accord rulebook.  Two months earlier, the Intergovernmental Panel on Climate Change (IPCC) released a report that the United Nations commissioned in 2016. Immediately, a dispute arose over whether to officially welcome the report or merely to note its availability.

The U.S., Russia, Saudi Arabia and Kuwait insisted that it be “noted” not “welcomed.”  Since the report is not “welcomed” by a consensus, many of the representatives were deeply annoyed.  Still, the tiff on wording should not prevent representatives from using the substance of the report.

The IPCC report repeats warnings of climate catastrophes, but with more urgency for staying at the low end of 1.5C to 2C degrees above the pre-industrial levels.

Specifically, the IPCC report said that by 2100 global sea level rise would be 10cm lower, with global warming of 1.5C compared with 2C.  Also, that extreme heatwaves will visit 14% of the world’s population at least once every five years at 1.5C.  Should temperatures rise by 2C.,  more than a third of the planet would suffer extreme heat.

At 2C, ice free summers are 10 times more likely, leading to greater habitat losses for polar bears, whales, seals and sea birds.  If warming is kept to 1.5C, coral reefs will decline by 70-90%. If temperatures rise to 2C, 99% of the world’s coral reefs would be lost.  These extremes can be translated into GDP losses, coastal flooding, agricultural losses, potable water stress, and misery for millions of people.

Coincident with release of the IPCC report, a study called Nature for Climate was released that detailed how the agriculture and forestry industries can reduce their contribution to atmospheric carbon emissions.  One part of the study focuses on the right mix of initiatives in the context of each U.S. state, and it balances the carbon dioxide reductions against the costs of initiatives at various levels of intensity.

This report produces recommendations that apply to industries other than transportation and electric power generation – the usual bete noir in climate discussions.  The report is far less preachy that we are accustomed to hearing.  It would be helpful if the UN adopts a similar measure of composure in its climate change studies and upcoming “rulebook.”