When we consider benchmarks that will help explain why the world ignored dire warnings of climate change, we will want to dwell on AR5, the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC) (www.ipcc.ch). The report, put together by some of the world’s most eminent climatologists, describes what can only be called the cataclysmic consequences of our unceasing pursuit of the hard-energy path to growth. One sentence says it all: “Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts.”
Only the most die-hard climate change deniers—and as we know, there are many, including more than half the Republicans in the US Congress—will turn their backs and close their ears to this report. (Actually, they probably won’t read a word of it.) As the deniers insist, “I’m not a scientist” (see my post #49). But then they should listen to those who are. The so-called core writing group that prepared AR5 consisted of 49 scientists—31 from the major industrialized countries (including 7 Americans), 8 from middle-income countries such as China, and 10 from low-income countries such as Sudan.
Here are some key findings (with italics in the original) from the full-length report, which is available at http://ipcc.ch/pdf/assessment-report/ar5/syr/SYR_AR5_LONGERREPORT.pdf:
- On atmospheric changes: “Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. The period from 1983 to 2012 was very likely the warmest 30-year period of the last 800 years in the Northern Hemisphere, where such assessment is possible (high confidence) and likely the warmest 30-year period of the last 1400 years (medium confidence). . . . Atmospheric concentrations of greenhouse gases are at levels that are unprecedented in at least 800,000 years.”
- Temperature: “It is virtually certain that there will be more frequent hot and fewer cold temperature extremes over most land areas on daily and seasonal timescales, as global mean surface temperature increases. It is very likely that heat waves will occur with a higher frequency and longer duration. . . . Extreme precipitation events over most mid-latitude land masses and over wet tropical regions will very likely become more intense and more frequent as global mean surface temperature increases.”
- Causation: “CO2 emissions from fossil fuel combustion and industrial processes contributed about 78% to the total GHG emission increase between 1970 and 2010, with a contribution of similar percentage over the 2000–2010 period (high confidence). . . . The contribution of population growth between 2000 and 2010 remained roughly identical to that of the previous three decades, while the contribution of economic growth has risen sharply (high confidence).”
- Our role: “The evidence for human influence on the climate system has grown since AR4. Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, and in global mean sea-level rise; and it is extremely likely to have been the dominant cause of the observed warming since the mid-20th century.”
- Consequences: “Impacts from recent climate-related extremes, such as heat waves, droughts, floods, cyclones, and wildfires, reveal significant vulnerability and exposure of some ecosystems and many human systems to current climate variability (very high confidence). Impacts of such climate-related extremes include alteration of ecosystems, disruption of food production and water supply, damage to infrastructure and settlements, human morbidity and mortality, and consequences for mental health and human well-being. For countries at all levels of development, these impacts are consistent with a significant lack of preparedness for current climate variability in some sectors.”
- Remedies: “Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems. Limiting climate change would require substantial and sustained reductions in greenhouse gas emissions which, together with adaptation, can limit climate change risks.”
- Bottom line: “Without additional mitigation efforts beyond those in place today, and even with adaptation, warming by the end of the 21st century will lead to high to very high risk of severe, widespread, and irreversible impacts globally (high confidence). . . . Limiting warming to 2.5 °C or 3 °C . . . would require substantial emissions reductions over the next few decades, and near zero emissions of CO2 and other long-lived GHGs [greenhouse gases] by the end of the century.”
The irresponsibility of the world’s governments when it comes to climate change will soon be on display in Lima, Peru, when leaders meet to consider a new agreement. The meeting will (once again) be heavy on rhetoric and light on substance. Some governments will agree to voluntarily curb greenhouse gas emissions, and a few of those will actually do so. (Sweden is the lead country when it comes to “going green,” moving toward relying for less than 20 percent of its energy on fossil fuels. See the global rankings at http://earthtechling.com/2014/10/swedens-environmental-leadership/?google_editors_picks=true; and thanks to Glen Jackson for this item.) But most countries will continue devoting far more resources (including subsidies) to fossil fuel extraction than to conservation and alternative energy.
What about the just-concluded verbal agreement on climate change between President Obama and China’s President Xi Jinping? Much ado about precious little, I’d say. Obama promised that the US would emit 26 to 28 percent less carbon dioxide in 2025 than it did in 2005—an easy promise, since he won’t be around to carry it out, and still far short of the reductions that need to take place. China’s promise was even less meaningful: allowing carbon dioxide emissions to peak “around 2030,” and by then to have renewable energy comprise 20 percent of China’s energy picture. Well, by 2030 (maybe), when Xi won’t be around either, China’s coal-driven economy will have further blackened the skies, and its consequent public health problems will have worsened considerably. So where’s the sacrifice?
Future historians—I assume there will be some—will be bewildered by such willful shortsighted and political slights-of-hand. As they peer out from their offices on the moon or some distant planet, they may wonder if the lesson of Earth’s failures at self-protection will be repeated.