Climate Change: The Coming Crisis
My Global Warming Man or Myth – The Science of Climate Change Web site was designed to show the average person why scientists agree that the climate is warming and that humans are mostly responsible. The next phase of the site will highlight the likely impacts of a rapidly warming world. As I develop these new pages, I will be posting them here hoping for your feedback to improve on the content. Once all of the impact pages are ready, I will publish them to the Web.
The General Overview page is the first of these blog posts.
“The research community provides much information to support discussions on ‘dangerous climate change’. Recent observations show that societies and ecosystems are highly vulnerable to even modest levels of climate change, with poor nations and communities, ecosystem services and biodiversity particularly at risk. Temperature rises above 2oC will be difficult for contemporary societies to cope with, and are likely to cause major societal and environmental disruptions through the rest of the century and beyond.” — Synthesis Report from the Climate Change Congress (2009)
“Climate change is occurring, is caused largely by human activities, and poses significant risks for—and in many cases is already affecting—a broad range of human and natural systems. Individually and collectively, these changes pose risks for a wide range of human and environmental systems, including freshwater resources, the coastal environment, ecosystems, agriculture, fisheries, human health, and national security, among others.” — U.S. National Research Council (2010)
Unfortunately, the equilibrium global surface air temperature change due to a doubling of CO2 from 280 ppm (pre-Industrial Revolution) to 560 ppm is likely to be in the range 2 to 4.5oC, with a best estimate of about 3oC, and is very unlikely to be less than 1.5oC (Knutti and Hegerl, 2008; IPCC, 2007). As this section of Web pages will reveal, 3 oC will have serious negative consequences for life on this planet.
Each of the items below will be a stand-alone page. This blog post is the General Overview page.
Sea Level Rise & the Coastal Environment
Ecosystems, Ecosystem Services, and Biodiversity
Agriculture, Fisheries, and Food Production
Allergies & Asthma
National and Human Security
Australia and New Zealand
Polar Regions (Arctic and Antarctic)
Global Tipping Points
Six Degrees: Our Future on a Hotter Planet
1 oC Warmer World
2 oC Warmer World
3 oC Warmer World
4 oC Warmer World
5 oC Warmer World
6 oC Warmer World
I highly recommend the following resources which were used extensively in this section of the Website:
- Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (2007)
- America’s Climate Choices: Panel on Advancing the Science of Climate Change; National Research Council (2010)
- Global Climate Change: Impacts in the United States; U.S. Global Change Research Program (2009)
- Six Degrees: Our Future on a Hotter Planet by Mark Lynas (2008)
According to IPCC WGII (2007):
- Observational evidence from all continents and most oceans shows that many natural systems are being affected by regional climate changes, particularly temperature increases.
- A global assessment of data since 1970 has shown it is likely that anthropogenic warming has had a discernible influence on many physical and biological systems.
- Other effects of regional climate changes on natural and human environments are emerging, although many are difficult to discern due to adaptation and non-climatic drivers.
- More specific information is now available across a wide range of systems and sectors concerning the nature of future impacts, including for some fields not covered in previous assessments.
- Magnitudes of impact can now be estimated more systematically for a range of possible increases in global average temperature.
- Impacts due to altered frequencies and intensities of extreme weather, climate and sea-level events are very likely to change.
- Some large-scale climate events have the potential to cause very large impacts, especially after the 21st century.
- Impacts of climate change will vary regionally but, aggregated and discounted to the present, they are very likely to impose net annual costs which will increase over time as global temperatures increase.
Figure 1 (IPCC, 2007) shows locations of significant changes in physical systems (snow, ice and frozen ground; hydrology; and coastal processes) and biological systems (terrestrial,marine, and freshwater biological systems), along with surface air temperature changes over the period 1970-2004. A subset of about 29,000 data series was selected from about 80,000 data series from 577 studies. These met the following criteria: (1) ending in 1990 or later; (2) spanning a period of at least 20 years; and (3) showing a significant change in either direction, as assessed in individual studies. It is clear that global warming has caused singificant changes in many physical and biological systems.
Figure 2 (IPCC, 2007) shows the key impacts of climate change as global average temperature rises toward 5 oC.
Figure 3 (IPCC, 2007) shows the possible impacts of climate change due to changes in extreme weather and climate events.
Next: Sea Level Rise & the Coastal Environment