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National Assessment of Climate Change: Part II

Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passions, they cannot alter the state of the facts and evidence.

— John Adams, President

United States of America

1797-1801 The Fourth National Climate Assessment (NCA4) was issued about two weeks ago, and I did a brief overview of it in last week’s column. This week, I’ll attempt to give readers an idea of what is contained within each of the 12 sections. In many cases, we’ll be exposed to facts, the kind that former Vice President Al Gore called “inconvenient truths,” that may be unsettling. I. Communities

The report states, “Climate change creates new risks and exacerbates existing vulnerabilities in communities across the United States, presenting growing challenges to human health and safety, quality of life, and the rate of economic growth.” It proposes that the impact of climate on life will threaten future prosperity because of problems caused by aging and deteriorating infrastructures, stressed ecosystems, and persistent economic inequality. People who are now vulnerable, will become even more victimized by extreme weather, and entire communities will suffer the consequences. II. Economy

The effects of climate change are expected to impede the rate of economic growth over the rest of this century. Agriculture, fisheries, and tourism are all vulnerable to extreme weather conditions. With greenhouse gas emissions increasing, annual losses are projected to be in the hundreds of billions of dollars. III. Interconnections

We rely on combinations of natural systems, human-made constructions, and social relationships. The result is that the full extent of climate change risks to interconnected systems may often be greater than the sum of risks to individual sectors. IV. Reducing Risks

The report emphasizes that “future risks from climate change depend primarily on decisions made today.” While many communities are taking steps to lower greenhouse gas emissions and implement adaptation strategies, more immediate and substantial national and global mitigation is needed to avoid severe long-term consequences. V. Water

Both the quantity and quality of water are essential to our survival. The report states, “Rising air and water temperatures and changes in precipitation are intensifying droughts, increasing heavy downpours, reducing snowpack, and causing declines in surface water quality, with varying impacts across regions.” Additionally, most U.S. power plants rely on a steady supply of water for cooling. Their operation will be negatively affected by changes in water availability and temperatures. VI. Health

Climate change creates extreme weather and climate-related situations that foster the transmission of disease through food, water, insects, and pests. Exposure to disease from waterborne and food-borne diseases is expected to increase. Moreover, increases in heat-related deaths are expected to outpace decreases in cold-related deaths. VII. Indigenous People

“Climate change increasingly threatens indigenous communities’ livelihoods, economies, health, and cultural identities by disrupting interconnected social, physical, and ecological systems.” Many indigenous people are reliant on resources that are particularly affected by alterations in land, water, coastal conditions, and natural resources. While some tribes are developing mitigation strategies through the development of renewable energy on tribal lands, others will be relocating, presenting challenges associated with maintaining cultural continuity. VIII. Ecosystems

It is not hyperbole to say that the ecosystem is the basis for the persistence of all other aspects of our existence. NCA4 points out that coral reef and sea ice ecosystems are already experiencing transformational changes. Clean air and water, coastal environments, wood and fiber, crop pollination, hunting and fishing, tourism, and more will continue to be degraded by the impact of climate change.

“Climate change,” according to the report, “has already had observable impacts on biodiversity, ecosystems, and the benefits they provide to society.” The degradation of our ecosystem will have a deleterious effect on outdoor activity, and “future generations can expect to experience and interact with the natural environment in ways that are different from today.” IX. Agriculture

As temperatures continue to creep upward, regions — like the Northern Great Plains — may experience an expansion in crop production. However, that will not offset the declines that are expected in the Midwest and Southwest due to extreme high temperatures. Projected increases in heat conditions “are expected to lead to further heat stress for livestock ...”

Because of decreases in agricultural and livestock production, the cost of such products is expected to increase across the world. NCA4 postulates that climate changes “threaten future gains in commodity crop production and put rural livelihoods at risk.” The report on this section concludes, “Rising temperatures, extreme heat, drought, wildfire on rangelands, and heavy downpours are expected to increasingly disrupt agricultural productivity in the United States.” X. Infrastructure

Our aging and deteriorating infrastructure poses cascading impacts on critical sectors of our society, like national security, health and well being, and essential services. NCA4 discusses the effects of droughts in some sectors and downpours in others as threats to pipelines, bridges, and power plants. It also points out that “continued increase in the frequency and extent of high-tide flooding … threatens America’s trillion-dollar coastal property ...” XI. Oceans and Coasts

Rising water temperatures, ocean acidification, retreating arctic sea ice, high-tide flooding, storm surges, and heavier precipitation put marine species at risk, decrease fishery productivity, and negatively affect communities that rely on marine ecosystems for livelihoods. XII. Tourism and Recreation

Climate change threatens economies based on coral-reef activities, winter sports, and inland water-based recreation. Of particular importance to California right now is the projection that increases in wildfire smoke will have a negative effect on all outdoor activities, as will declines in snow and ice cover. The report claims that “these and other climate-related impacts are expected to result in decreased tourism revenue in some places and, for some communities, loss of identity.”

I think it is both interesting and foreboding that NCA4 doesn’t consider the possibility of reversing climate change. Instead it concentrates on mitigating it, adapting to it, and possibly slowing it down. My hope, after plowing through the report, is that Abraham Lincoln was our most prescient president when he said:

I am a firm believer in the people. If given the truth, they can be depended upon to meet any national crisis. The great point is to bring them the real facts.

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Jim Glynn may be contacted at

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