You Can’t Ignore the Future: 5 Reasons Climate Science Looks Beyond 2040

Yesterday it was reported that the Trump administration is redoubling its efforts to undermine climate science. James Reilly, head of the US Geological Survey, reportedly instructed scientists in the office to limit projections of climate impacts to just 2040. Studies typically project out to 2100. It is nearly the end of May 2019.  Failing to look beyond 2040 is like pretending a baby born today won’t live past 21.  As with many life plans, like mortgages signed onto today, climate science routinely looks past the year 2040.  Here are five reasons why:

Figure 1. Carbon dioxide lingers a long time in the atmosphere.

1. Due to Earth’s carbon cycle, carbon dioxide (CO₂) released by burning coal, oil, and gas today will be trapped in the atmosphere for decades to thousands of years. The more that is released the longer it lingers in the atmosphere (see figure 1).
2. Climate change is largely “baked in” over the next decade and starts to diverge after that (see figure 2). This means that without near-term changes, some of the climate impacts we would see would be irreversible even if we decrease atmospheric carbon dioxide later on in the century.
3. Governments around the world, including the US and the federal agencies that comprise the US Global Change Research Program (including the Department of the Interior, of which the USGS is a part), monitor and report the human activities that overload our atmosphere with carbon, other heat-trapping gases, and aerosols. These climate calculations ensure business leaders; planners; and local, state and national governmental leaders have the most up-to-date tools needed to make informed decisions on behalf of people living in the US.
4. 

   Figure 2. Global carbon emissions and associated global average temperature change.

   Most parties to the United Nations Framework Convention on Climate Change, as stated in goals of the Paris Agreement, have committed to holding Earth’s global average surface temperature to well below 2 degrees Celsius (or 3.6 degrees Fahrenheit). We won’t stop working on limiting the rise in global average surface temperature after 2040.

5. Congress, back in the first Bush Administration, recognized the need for examining climate in the long-term. The Global Change Research Act of 1990, which established the US Global Change Research Program, states that the research plan (emphasis added) “shall provide for, but not be limited to the following research elements: (1) Global measurements, establishing worldwide observations necessary to understand the physical, chemical, and biological processes responsible for changes in the Earth system on all relevant spatial and time scales… (4) Predictions, using quantitative models of the Earth system to identify and simulate global environmental processes and trends, and the regional implications of such processes and trends.” Furthermore, the Act requires that the scientific assessment (the National Climate Assessment) “analyz[e] current trends in global change, both human-inducted [sic] and natural, and projects major trends for the subsequent 25 to 100 years.”

In other words, the science allows us (and the law requires us) to look beyond the next 21 years to gauge the coming impacts we may face as the climate crisis mounts. As long as agencies follow the laws of the US, the Department of Defense, NASA, the Department of Commerce (including NOAA), the Department of the Interior, the Department of Health and Human Services, and the other agencies that contributed to the National Climate Assessment should continue to provide the latest evidence and update outlooks up to and continuing past 2040 to ensure the health, safety and economic prosperity of those living in the US.