A paper by the American Association for the Advancement of Science provides a superb, highly concise, summary of where we stand and what we can do about climate change
Being a writer myself—and one who likes to convey complex concepts clearly and concisely—I was tremendously impressed by a report released a few months ago by the American Association for the Advancement of Science: What We Know: The Reality, Risks, and Response to Climate Change.
AAAS is the leading association of scientists in the U.S. and publisher of the journal Science.
In just eight pages of text, What We Know presents three key messages on climate change:
1. Climate scientists agree that climate change is happening here and now. From the report: “Based on well-established evidence, about 97% of climate scientists conclude that humans are changing the climate.” To explain how a changing climate relates to individual weather events, such as Hurricane Sandy, the report uses the analogy of steroid use in baseball: “Greenhouse gases have supercharged the climate, just as steroids supercharged hitting in Major League Baseball. Over the course of a baseball season in the steroid era, we witnessed more—and longer—home runs, even though we cannot attribute any specific homer to steroids.”
Climate change is causing a shrinkage of Arctic sea ice, an acceleration of ice sheet melting in Greenland and Antarctica, ocean acidification (at a more rapid rate than at any time in 300 million years), sea level rise, floods, heat waves, droughts, wildfires, human health impacts, and ecological impacts, including species extinctions. It is also affecting national security—the report references the 2014 Quadrennial Defense Review from the U.S. Department of Defense and National Security Implications of Climate Change for U.S. Naval Forces, a 2011 report from the National Research Council.
2. We are at risk of pushing our climate system toward abrupt, unpredictable, and potentially irreversible changes with highly damaging impacts. The report discusses both “high-risk scenarios” (the potential for impacts at the high end of the ranges of what scientists expect relative to temperature rise, sea level rise, flooding, and droughts) and abrupt climate change.
Abrupt climate change refers to positive feedback loops that could cause sudden, dramatic change. The report notes that geological history shows instances in which “a relatively small change in one element of climate led to abrupt changes in the system as a whole.” There is risk that “pushing global temperatures past certain thresholds could trigger abrupt, unpredictable, and potentially irreversible changes that have massively disruptive and large-scale impacts.” Such impacts could result from Arctic sea ice melting, large-scale ice sheet collapse, destabilization of sea floor methane, and melting of permafrost.
3. The sooner we act the lower the risk. The report concludes with decidedly policy issues: “As we continue to increase greenhouse gas emissions, we accelerate and compound the effects and risks of climate change into the future. Conversely, the sooner we make a concerted effort to curtail the burning of fossil fuels as our primary energy source and releasing the CO2 into the air, the lower our risk and cost will be.”
The report points to U.S. and international efforts to address threats of acid rain and ozone depletion once those threats were identified. (Indeed, the chair of the AAAS task force that created this report is Mario Molina, who shared the 1995 Nobel Prize in Chemistry for identifying ozone depletion as a concern.) The challenges with climate change will be greater, but the report’s authors believe that once our nation is convinced that something has to be done, we will put our ingenuity to work and make it happen.
While in some parts of the country there has been a backlash against science, I remain doggedly optimistic that sooner or later the public will come to its collective senses and take dramatic action to curtail greenhouse gas emissions. Reports, such as this (which was just translated into Spanish), will make that happen sooner rather than later.
The full report, which you can digest in an hour, is available for downloading from AAAS.