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Fifth National Climate Assessment Released

This week the Fifth National Climate Assessment, which is a Congressionally mandated inter-agency  study of the impacts of climate change, was released.The Climate Assessment is issued ever four years as an analysis of the progress of climate change and efforts to curtail it impacts.

As noted in the introductory portion of the Assessment:

“The more the planet warms, the greater the impacts. Without rapid and deep reductions in global greenhouse gas emissions from human activities, the risks of accelerating sea level rise, intensifying extreme weather, and other harmful climate impacts will continue to grow. Each additional increment of warming is expected to lead to more damage and greater economic losses compared to previous increments of warming, while the risk of catastrophic or unforeseen consequences also increases. …

However, this also means that each increment of warming that the world avoids—through actions that cut emissions or remove carbon dioxide (CO2) from the atmosphere—reduces the risks and harmful impacts of climate change. While there are still uncertainties about how the planet will react to rapid warming, the degree to which climate change will continue to worsen is largely in human hands. …

In addition to reducing risks to future generations, rapid emissions cuts are expected to have immediate health and economic benefits ,,,. At the national scale, the benefits of deep emissions cuts for current and future generations are expected to far outweigh the costs.”

The report goes into significant detail regarding the risks from climate change and the benefits of reducing the factors that are leading to and exacerbating the impacts of climate change.

“Harmful impacts will increase in the near term

Even if greenhouse gas emissions fall substantially, the impacts of climate change will continue to intensify over the next decade (see ‘Meeting US mitigation targets means reaching net-zero emissions’ …Box 1.4), and all US regions are already experiencing increasingly harmful impacts. Although a few US regions or sectors may experience limited or short-term benefits from climate change, adverse impacts already far outweigh any positive effects and will increasingly eclipse benefits with additional warming….

In coastal environments, dry conditions, sea level rise, and saltwater intrusion endanger groundwater aquifers and stress aquatic ecosystems. Inland, decreasing snowpack alters the volume and timing of streamflow and increases wildfire risk. Small rural water providers that often depend on a single water source or have limited capacity are especially vulnerable….

As the climate changes, increased instabilities in US and global food production and distribution systems are projected to make food less available and more expensive. These price increases and disruptions are expected to disproportionately affect the nutrition and health of women, children, older adults, and low-wealth communities….

Homes, property, and critical infrastructure are increasingly exposed to more frequent and intense extreme events, increasing the cost of maintaining a safe and healthy place to live….

More severe wildfires in California, increasing sea level rise in Florida, and more frequent flooding in Texas are expected to displace millions of people. Climate-driven economic changes abroad, including reductions in crop yields, are expected to increase the rate of emigration to the United States. “

The Assessment also notes the significant impacts on all aspects of the national infrastructure.

“ Many infrastructure systems across the country are at the end of their intended useful life and are not designed to cope with additional stress from climate change. For example, extreme heat causes railways to buckle, severe storms overload drainage systems, and wildfires result in roadway obstruction and debris flows. Risks to energy, water, healthcare, transportation, telecommunications, and waste management systems will continue to rise with further climate change, with many infrastructure systems at risk of failing. ”

It also notes the disproportionate impacts on specific groups.

“ While climate change can harm everyone’s health, its impacts exacerbate long-standing disparities that result in inequitable health outcomes for historically marginalized people, including people of color, Indigenous Peoples, low-income communities, and sexual and gender minorities, as well as older adults, people with disabilities or chronic diseases, outdoor workers, and children.”

The Assessment concludes that despite a decrease in carbon emissions in recent years and increasing efforts to address the impacts of climate change not enough has been done.

“Despite an increase in adaptation actions across the country, current adaptation efforts and investments are insufficient to reduce today’s climate-related risks and keep pace with future changes in the climate. Accelerating current efforts and implementing new ones that involve more fundamental shifts in systems and practices can help address current risks and prepare for future impacts (see ‘Mitigation and adaptation actions can result in systemic, cascading benefits’ …).”