Adapting to Climate Change Some Difficulties 831 Signal Detection

Adaptation at the farmer level requires three basic steps: detecting a shift in one's external environment, determining that it would favor a change in behavior, and undertaking that change (Hanemann 2000; Kandlikar and Risbey 2000). Thus the first step in adapting to climate change requires detecting the signal of climate change in the noise of climate variability. Given the amplitude of climate variability in many regions, this might be no small task.

Figure 8.1 illustrates this detection problem, showing historical and projected future trends in temperature and precipitation for millet areas in Niger based on the GFDL climate model, which happens to project much larger decreases in precipita-

1960 1966 1972 1978 1984 1990 1996 2002 2008 2014 2020 2026 2032 2038 2044 2050

Fig. 8.1 Historical and projected future changes in temperature (top panel, in °C) and precipitation (bottom panel, in mm) for millet growing areas in Niger, 1960-2050. Data left of the vertical line are observed (CRU), and data to the right are based on projected changes from the GFDL climate model for the A1B scenario, assuming similar variability to the historical data. Grey boxes represent the range of historical variability between 1960 and 2002

Fig. 8.1 Historical and projected future changes in temperature (top panel, in °C) and precipitation (bottom panel, in mm) for millet growing areas in Niger, 1960-2050. Data left of the vertical line are observed (CRU), and data to the right are based on projected changes from the GFDL climate model for the A1B scenario, assuming similar variability to the historical data. Grey boxes represent the range of historical variability between 1960 and 2002

tion in the Sahel (around 25% declines by 2050) than most other climate models. For temperature (top panel), the signal of climate change quickly emerges from the noise of past temperature variability, with every growing season hotter than the hottest year on record after around 2030 - a result we should expect for much of the tropics (Battisti and Naylor 2009). This is not the case with precipitation. Despite a very large projected decrease in average annual precipitation for millet-growing regions in Niger in this model, most years remain well within historical variability, potentially obscuring the underlying drying trend.

Farmers in developed countries have access to a wealth of climate and weather data, and so presumably could learn about trends in climate without having to sense them independently. The same is often not true for farmers in poorer countries, who rely on various traditional methods for climate forecasting, and who might be more or less on their own in discerning longer-run climate shifts.

Evidence is mixed on farmers' ability to correctly perceive such longer-run shifts. Meze-Hausken (2004) finds that farmers in northern Ethiopia report a decline in rainfall where rainfall gauges report no change. Maddison (2007) shows mixed results in farmers' ability to correctly perceive climate shifts across a range of African countries, with farmers in many countries correctly recognizing trends in mean temperature and rainfall, and others reporting trends in disagreement with observed climate data. Thomas et al. (2007) find qualitative evidence of South African farmers' abilities to detect subtle changes in mean state and variability of climate, but it is unclear whether this reveals actual recognition of trends, or the tendency to overestimate the frequency of negative events (Cooper et al. 2008).

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

Get My Free Ebook


Post a comment