Thomas Fire – Santa Barbara County – Southern California – December 12, 2017
Photo Credit: Mike Eliason/Santa Barbara County Fire Department

 

Here in California, after years of drought, ferocious wildfires have consumed the tinder and everything in their path. Ignited on December 4, 2017, the Thomas Fire was not fully contained until January 12, 2018. Now ranked as the largest fire in California’s modern history, it burned about 281,900 acres, equivalent to the size of Dallas and Miami combined. It destroyed 1,063 structures and damaged another 280.

Torrential rainfall on January 9, a welcome respite for firefighters, brought more distress to residents in the area. Mudslides roared down fire scarred slopes, destroying and damaging hundreds of homes, as well as commercial property. Twenty people lost their lives; three are still missing.

Home damaged by mudslides – Montecido – Santa Barbara County – Southern California
January 10, 2018
Photo Credit: Kenneth Song/Santa Barbara News

 

Meanwhile, extreme winter weather on America’s East Coast provides vindication for climate change deniers. But, as world-renowned climate scientist Dr. Michael Mann explains, this is “an example of precisely the sort of extreme winter weather we expect because of climate change.” What’s happening is the collision of increasingly warm Atlantic Ocean waters with cold Arctic air masses. To make matters worse, the warmer oceans also mean more moisture in the atmosphere to fuel the storm and produce larger snowfalls.

Woman walks down street in East Boston – Massachusetts – January 4, 2018
Photo Credit: Michael Dwyer/AP

 

In November 2017, the U.S. Global Change Research Program released its 477-page Climate Science Special Report (CSSR), in compliance with regulations issued by the Department of Commerce/National Oceanic and Atmospheric Administration (NOAA). The CSSR is “designed to be an authoritative assessment of the science of climate change, with a focus on the United States, to serve as the foundation for efforts to assess climate-related risks and inform decision making about responses.”

Based on extensive evidence obtained from thousands of studies conducted by researchers around the world, the authors of the CSSR conclude that “it is extremely likely [95%-100% chance] that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.”

As the following highlights of the CSSR indicate, climate change continues unabated:

• Global and U.S. temperatures continue to rise. Across America, the annual average temperature has increased by 1.8℉ (1.0℃) for the period 1901-2016 and is projected to rise.
• Many temperature and precipitation extremes are becoming more common. In the past two decades, the number of U.S. high-temperature records far exceeds that of low-temperature records. Since 1901, heavy precipitation events have increased in both intensity and frequency, especially in the northeastern states.
• Oceans are rising, warming, and becoming more acidic. The world’s oceans have absorbed about 93% of the excess heat caused by greenhouse gas warming. This not only makes them warmer, altering global and regional climate feedbacks, but also more acidic with detrimental impacts on marine life. Since 1900, global mean sea level has risen by about 7-8 inches (about 16-21 cm). Rates of sea level increase are accelerating in over 25 Atlantic and Gulf Coast cities.
• Climate change in Alaska and across the Arctic continues to outpace global climate change. Alaska’s permafrost is thawing and becoming more discontinuous; this process releases more carbon dioxide and methane resulting in additional warming. Arctic sea ice loss is expected to continue with a 90% chance of resulting in nearly sea ice-free summers by the 2040s.
• Limiting globally averaged warming to 2℃ (3.6℉) will require major reductions in emissions.

The CSSR makes it clear that human activities are now the dominant cause of the observed trends in climate. With the global mean atmospheric carbon dioxide concentration exceeding 400 ppm, a level that last occurred about 3 million years ago, the choices our generation make today will determine the magnitude of climate change risks beyond the next few decades. As critical thresholds are crossed, unanticipated and difficult or impossible-to-manage changes in the climate system are possible throughout the next century.

You can read the full report here.