Climate Science Special Report
The New York Times obtained and posted a report drafted by 30+ scientists from across federal agencies, universities, and other research institutes. The report outlines how climate research has advanced and what has been learned since a previous report published in 2014. The report is highly revealing of scientific impressions of the global climate. I want to highlight here a few of the more startling findings:
> Weather is what is happening now in the atmosphere. Climate concerns patterns, of which weather is only a part. Climate change indicates shifts in these identifiable patterns.
> The world has warmed 1.6F over past 150 years, rising roughly in parallel with industrialization.
> Evidence for changing climate “abounds,” according to the report:
“Thousands of studies conducted by tens of thousands of scientists arond the worl have documented changes in surface, atmospheric, and oceanic temperatures; melting glaciers; disappearing snow cover; shrinking sea ice; rising sea level; and an increase in atmospheric water vapor.” (p.11)
> Evidence also demonstates that human activities, “especially emissions of greenhouse gases, are primarily responsible for recent observed climate changes.” The drafters couldn’t put the point more clearly: recent warming is ANTHROPOGENIC. In fact, to remove any doubt as to their meaning, the drafters state “there are no alternative explanations, and no natural cycles are found in the observational record that can explain the observed changes in climate.” In other words, climate change is not explainable by fluxuations in natural cycles.
> The past few years have seen record-breaking temperatures, including some of the warmest years on record. Since the 2014 report, 2015 was considerably warmer than 2014, and 2016 was very much warmer than 2015.
> The reports’ measured prognosis is bleak. Average temperature of the contiguous United States is expected to rise over the next century. Even if all greenhouse emissions were to cease immediately, warming would still uptick 0.5F. This is of course an impossibility. The report therefore projects a 2.5F near-term increase over the next few decades, even under significantly reduced emissions. Almost every year to come will be record setting. By late century, warming projections are 5.0F on the low side and 8.7F on the high side, emissions being the primary variable.
> Extreme weather events will become more frequent and intense, especially precipitation and drought. Evidence bears this out clearly: colder winters, rainier wet seasons, drier droughts. Extreme precipiation, for example, has increased across the U.S.
> More than 90% of extra heat trapped inside the climate system by human human emissions is being absorbed by oceans, and thus oceans are rapidly acidifying, altering currents and depleting (already overfished) fisheries.
> Global sea level has risen approximatley 8–9 inches since 1880. Sea levels will likely rise another half foot by 2030, another foot by 2050, and 1–4 feet by 2100. The threats to ocean ecosystems are well documented.
> Photographic evidence of melting at the Arctic cap is breathtaking, and it is the thinning that most alarms the drafters. (See especially p.28 of the report).
> A final surprise: “there is a significant possibility for unanticipated changes.” (28) Modeling of our future experience is sometimes difficult. Drafters propose two types of “surprise” we may encounter: (1) “Compound Events, where multiple extreme climate events occur simultaneously or sequentially,” and (2) “critical threshold” or “tipping point events.” The probabily of such events rises as human influence on climate increases.
