Draft 3rd U.S. climate assessment: Cut emissions, get prepared - Business, Government Legal News from throughout WV

Draft 3rd U.S. climate assessment: Cut emissions, get prepared

Posted: Updated:

Given new and stronger evidence pointing to a human role in changing the climate, more needs to be done to reduce climate-warming emissions and to adapt by building resiliency into systems.

These are among the findings and suggestions in the draft third National Climate Assessment, released Jan. 11.

Climate assessments are required periodically by 1990 U.S. law. The first National Assessment was completed in 2000, and the second in 2009. This third assessment was drafted by the 60-member National Climate Assessment Development Advisory Committee. None of those members are located in West Virginia.

In the U.S., the average temperature has increased by about 1.5 degrees Fahrenheit since 1895, according to the draft third assessment, with about 80 percent of that taking place since 1980. Some extreme weather and climate events have increased, and a continually growing body of evidence indicates that many of the increases are related to human activities.

The assessment considers the future under low-emissions and high-emissions scenarios. Combined with other assumptions, these lead to U.S. temperature rise ranging from less than 4 degrees to greater than 11 degrees by the end of the century, and to sea-level rise ranging from 8 inches to 6 feet 8 inches.

These are not the outside possibilities: The current emissions path would mean even greater warming than the high-emissions scenario, while targets called for in international agreements would require even larger emissions reductions than the low-emissions scenario.

The draft assessment observes threats from climate change across all aspects of human health and well-being, including extreme weather events, decreased air quality, diseases transmitted by insects and other vectors, damage to infrastructure, disruption of water supplies, adverse effects on crops and livestock, and changes in biodiversity and location of species, both on land and in the oceans.

"While some changes will bring potential benefits, such as longer growing seasons, many will be disruptive to society because our institutions and infrastructure have been designed for the relatively stable climate of the past, not the changing one of the present and future," the draft assessment reads.

Some additional warming is unavoidable based on past emissions but, "beyond the next few decades, the amount of climate change will still largely be determined by choices society makes about emissions. Lower emissions mean less future warming and less severe impacts; higher emissions would mean more warming and more severe impacts," it reads.

The assessment acknowledges in particular the difficulty of studying and preparing for the effects of climate change, given both the large role that society's unknowable choices play and the scant data on extreme weather events and on tipping points.

And the authors remind readers that the longer action is delayed, the more mitigation — cutting emissions — and adaptation — building resiliency into systems — will cost.

The assessment suggests action in several realms.

  • Although U.S. emissions have fallen recently, more mitigation is needed, the authors say. Current policies and practices are not consistent with the low-emissions scenario.
  • Adaptation is needed for a wide variety and intensity of climate effects. Updated building codes and landscaping ordinances are needed, for example, for energy efficiency, to conserve water supplies, to reduce susceptibility to heat stress and to protect against extreme weather. Decision-making processes need to be made more flexible, robust and resilient.
  • Continued improvement in scientific understanding will help with forecasts. For example, lack of knowledge of mechanisms controlling the rate of ice loss is making it difficult to narrow the range of future sea level rise.
  • A sustained climate assessment process to more efficiently synthesize the rapidly changing science would help supply timely information to decision-makers.

Comments are solicited on the draft assessment and may be submitted online during a public review period that lasts until April 12.

The final assessment is expected to be released in early 2014.

Powered by WorldNow
All content © Copyright 2000 - 2014 WorldNow and WVSTATE. All Rights Reserved.
For more information on this site, please read our Privacy Policy and Terms of Service.