The topics covered in this chapter can be summarized as follows:
|15.1 Increasing Temperatures
|The Earth’s average temperature increased by about 1° C from 1960 to 2020, with the greatest increases at far northern latitudes. This warming has led to more intense evaporation and that has contributed to an increase in wildfire activity in many areas. But the warming air can also hold more moisture, which has led to greater precipitation in some areas, in many cases with extreme outcomes. The greater warmth of the atmosphere is slowly being transferred to the oceans.
|15.2 Melting Glacial Ice and Permafrost
|Melting of glacial ice is accelerating and that is putting water supplies for humans and for ecosystems at risk. There is an increased risk of slope failure in in areas where valley glaciers have receded. Glacial melt is contributing to sea-level rise, and so to loss of habitable land and loss of groundwater resources. Permafrost is also melting faster, leading to slope instability and release of more greenhouse gases.
|15.3 Extreme Weather Events
|Climate warming is contributing to an increase in the incidence of tropical storms, which are bringing more intense flooding in coastal areas and inland, more slope failure. In the past few decades there has been a massive increase in the human and financial cost of natural disasters
|15.4 Climate Change and Earth Systems
|Climate change is contributing to changes in many Earth-system processes, including glacial processes, weathering and erosion, terrestrial ecosystems, aquatic and marine ecosystems and the intensity of the hydrological cycle.
|15.5 Taking Climate Action
|Some of the things we can do to help reduce climate change include: voting for candidates that understand climate change and have pledged to act accordingly, letting politicians know that climate change is the main issue, supporting only climate-friendly businesses and letting other businesses know why we don’t support them, driving much less by walking, biking and taking transit, avoiding all unnecessary trips, driving a smaller car or an electric car, eating less red meat and more locally produced food from small farms, and sending much less organic matter to the landfill.
Answers for the review questions can be found in Appendix 1.
- Explain why climate change has affected wildfire activity in many parts of the world.
- Why has there been greater warming at northern latitudes than in other regions?
- Why does global warming lead to increased precipitation in some areas?
- How can the thinning and recession of a glacier contribute to the probability of slope failure?
- Figure 15.2.7 shows that global sea level rose 25 mm from 1880 to 1900. What is the annual rate of sea-level rise during that time, and how does that compare with the annual rate from 2000 to 2013?
- In what way is the breakdown of permafrost a positive feedback to climate warming?
- Why are tropical storms more frequent and stronger as a result of climate change, and why are they bringing more precipitation onto land than has been the case in the past?
- For what reasons does climate change lead to enhanced weathering of rocks?
- What is the most important thing that you can do to help reduce climate change?