What is Climate Change?
Carbon, water and other basic chemical elements cycle through the Earth - from living to non-living, from atmosphere to land to sea, and from soils to plants. There are storage points or sinks throughout these cycles that hold these elements and keep the cycles balanced. For example, underground reserves of carbon and large expanses of forests are considered important sinks for carbon. When humans burn fossil fuels, a disproportionate amount of carbon is put into the atmosphere as carbon dioxide (CO2). When forests are removed to expand urban areas, less trees are available to take up carbon as part of photosynthesis.
Carbon dioxide and other gases act like a blanket around the Earth, trapping energy in the atmosphere and causing it to warm. This phenomenon is called the greenhouse effect and is natural and necessary to support life on Earth. However, the buildup of greenhouse gases can change Earth's climate. Even small changes in the average temperature of the planet can translate to large and potentially dangerous shifts in climate and weather. Many places have seen changes in rainfall, resulting in more floods, droughts, or intense rain, as well as more frequent and severe heat waves. The planet's oceans and glaciers have also experienced some big changes - oceans are warming and becoming more acidic, ice caps are melting, and sea levels are rising.
How has Las Cruces been impacted by weather events in the past?
Thanks to the generous support of the National Oceanic and Atmospheric Administration (NOAA), the City of Las Cruces worked collaboratively with a project team of climatologists* to identify critical extreme weather thresholds for Las Cruces, analyze the best available climate projections to identify future changes relative to those thresholds, interpret that information, and develop and implement strategies to prepare for those impacts. The first step was to define historical extreme weather events in the region and consider what climatic characteristics were most problematic.
How will climate change impact Las Cruces in the future?
Through the grant, renowned climatologist, Katherine Hayhoe, was commissioned to generate climate model data for the climatic characteristics that historically proved to be problematic. During a second workshop on April 27, 2016, City and agency participants learned more from Dr. Hayhoe.
To learn more, see a recording of Hayhoe’s presentation, (please note: the initial 5 minutes of the presentation are missing.) The team of climatologists also provided a presentation to the public.
Some key results:
Hotter. Climate change projections for Las Cruces suggest more frequent extreme heat days, warm nights, and greater risk of prolonged multi-day heat events, with implications for public health, including the safety of indigent populations, and the possibility of longer breeding seasons for disease-carrying insects. Associated with increased temperatures is a roughly 35% increase in cooling degree days, which implies increased need and demand for air condition, cooling and, by association, electricity—all of which will increase costs to residents and businesses.
Less cold. Climate models also project a longer freeze-free season, with many fewer freezing cold nights and a longer growing season, which may bring some benefits, in terms of decreased heating demand, but also some challenges in terms of possibly increased crop water demand, during the growing season, and increased risks associated with crop pests and diseases.
Precipitation. Drought risk will increase, as a result of higher temperatures accompanied by warm season precipitation totals similar to those in the historic record. Models project a slight increase in the number of days per year with more than 2.5 inches of rain in 24 hours in Las Cruces, which may increase flood risks in this already flood-prone region.
*Special thanks to the Project Team The project team was led by Adaptation International, an Austin, Texas non-profit that seeks to bridge the gap between climate change science and community action. Regional partners for the Las Cruces shared learning dialogue include the University of Arizona (including the Climate Assessment for the Southwest), I-S-E-T International, ,Texas Tech University Climate Science Center and New Mexico State University.