The United States Global Change Research Program (USGCPR), established by Presidential Initiative in 1989 and mandated by Congress in the Global Change Research Act of 1990, just released the Fourth National Climate Assessment (NCA4), which includes two volumes:
- The Climate Science Special Report (CSSR, NCA4 Vol. I)
- Impact, Risks, and Adaptation in the United States (NCA4 Vol. II).
To date, three previous NCA reports have been released. The first was published in 2000 and the second in 2009. The third NCA, “Climate Change Impacts in the United States”, was published in 2014. NCA4 builds on the work of these previous assessments. Both volume I and II of NCA4 are technical scientific assessments written by an extensive team of scientists from Federal agencies, academia, and the private sector. These authors were nominated through a public process and selected for their expertise in their respective fields of study.
The CSSR is a scientific analysis that primarily integrates, evaluates, and interprets the findings of climate and climate changes, and discusses the uncertainties associated with such findings. The NCA4 Vol. II mainly addresses impacts and current trends influenced by both humans and natural forces, as well as projected trends for the next 25 to 100 years.
Climate is changing rapidly and consistently compared to the natural variations in climate that have observed throughout our history. Observational evidence does not support credible natural explanations for a 1.7-degree F warming from 1901 to 2016. Robust scientific evidence consistently points toward the emissions of greenhouse gases by human activities as being the major cause.
Here we briefly recap the summary information of key messages and major findings for the Southern Great Plains (SGP) including Kansas, Oklahoma, and Texas.
Main Scientific Findings for the Southern Great Plains:
- Days > 100 degrees F projected to increase by up to 30-60 days per year
- Annual average temperature increase of 3.6 to 5.1 degrees F by the mid-21st century
- Historical sea level rise of 5-17 inches along the Gulf coast, with a projected further increase of 1-4 feet by 2100
- Increases in both extremely heavy rainfall, and drought
- Increases in damaging storm surges when tropical cyclones occur
- Future trends in tropical cyclone frequency, tornadoes, and severe local storms are uncertain
- Decreases in winter weather and extreme cold
Key Messages for the Southern Great Plains:
- Quality of life in the region will be compromised as increasing population, the migration of individuals from rural to urban locations, and a changing climate redistribute demand at the intersection of food consumption, energy production, and water resources. A growing number of adaptation strategies, improved climate services, and early warning decision support systems will more effectively manage the complex regional, national, and international issues associated with food, energy, and water.
- The built environment (e.g. buildings and other human-made infrastructure) is vulnerable to increasing temperature, extreme precipitation, and continued sea level rise, particularly as these structures age and populations shift to urban centers. Along the Texas Gulf Coast, relative sea level rise of twice the global average will put coastal infrastructure at risk. Regional adaptation efforts that harden or relocate critical infrastructure will reduce the risk of climate change impacts.
- Terrestrial and aquatic ecosystems are being directly and indirectly altered by a changing climate. Some species can adapt to extreme droughts, unprecedented floods, and wildfires from a changing climate, while others cannot, resulting in significant impacts to both services and people living in these ecosystems. Landscape-scale ecological services will increase the resilience of the most vulnerable species.
- Health threats, including heat illness and diseases transmitted through food, water, and insects, will increase as temperature rises. Weather conditions supporting these health threats are projected to be of longer duration or occur at times of the year when these threats are not normally experienced. Extreme weather events with resultant physical injury and population displacement are also a threat. These threats are likely to increase in frequency and distribution and are likely to create significant economic burdens. Vulnerability and adaptation assessments, comprehensive response plans, seasonal health forecasts, and early warning systems can be useful adaptation strategies.
- Tribal and indigenous communities are particularly vulnerable to climate change due to water resource constraints, extreme weather events, higher temperatures, and other likely public health issues. Efforts to build community resilience can be hindered by economic, political, and infrastructure limitations, but traditional knowledge and intertribal organizations provide opportunities to adapt to the potential challenges of climate change.
Climate change leads to an increase in average temperatures as well as the frequency, duration, and intensity of extreme heat events and a reduction in extreme cold events. For examples, by late in the 21st century, if no reductions in emissions take place, the region is projected to experience an additional 30–60 days per year above 100degrees F than it does now (Figure 1).
Figure 1. Projected increase in number of days above 100 degrees F. Note that the RCP 4.5 and 8.5 represents the representative concentration paths for equivalent 1370 ppm and 650 ppm CO2 concentration in year 2100, respectively.
For the complete report, readers can access the following links for the two volumes of the Fourth National Climate Assessment : Volume I: https://science2017.globalchange.gov/ and Volume II: https://nca2018.globalchange.gov.
Xiaomao Lin, State Climatologist
Mary Knapp, Assistant State Climatologist