CleanBeta

Notes on Global Warming

Proposed Climate Change Legislation by Ultimate Reductions Targets

Climate change is riddled with deep uncertainty about basic questions, which results from factors such as lack of information, disagreement about what is known or even knowable, linguistic imprecision, statistical variation, measurement error, approximation and subjective judgment on the structure of the climate system. These problems are compounded by the global scale of climate change, which produces varying impacts at local scales, long time lags between forcing and its corresponding responses, very long-term climate variability that exceeds the length of most instrumental records, and the impossibility of before-the-fact experimental controls or empirical observations.

While climate modeling has become both more complex and more accurate, scientists still have to deal with an enormous amount of uncertainty. One gaping unknown in climate change modeling is how much the global mean temperature will rise as a result of a doubling of CO2 concentrations in the atmosphere. Many scientists have done extensive empirical and modeling research on this subject, and most have found that most climate sensitivity estimates fall somewhere within the IPCC’s range of 1.5-4.5 degrees Celcius. However, more recently some have estimated it could be lower than 1.5 degrees Celcius or it could be an alarming 6 degrees Celcius or higher. (Keep in mind that a 5-7 degree Celcius drop in temperature is all that separates Earth’s present climate from an ice age).

In the past few centuries, atmospheric carbon dioxide has increased by more than 30 percent, and virtually all climatologists agree that the cause is human activity, predominantly the burning of fossil fuels and, to a considerable extent, land uses such as deforestation. Although there is not a The greenhouse phenomenon is well-understood and solidly grounded in basic science. In addition, it is scientifically well-established that the Earth’s surface air temperature has warmed significantly, by about 0.7°C since 1860, and that an upward trend can be clearly discerned by plotting historical temperatures. Such a graph would show a rapid rise in temperature at the end of the twentieth century. Furthermore, it is well-established that human activities have caused increases in radiative forcing, with radiative forcing defined as a change in the balance between radiation coming into and going out of the earth-atmosphere system.

If the Earth’s atmosphere near the surface warms somewhere between 1.4 and 5.8 degrees Celcius by 2100, likely effects will include: more frequent heat waves; more intense storms and a surge in weather-related damage; increased intensity of floods and droughts; warmer surface temperatures, especially at higher latitudes; more rapid spread of vector-borne disease; loss of farming productivity in warm climates and movement of farming to other regions, most at higher latitudes; rising sea levels, which could inundate coastal areas and small island nations; and species extinction and loss of biodiversity.

Perhaps the most important policy change that needs to be implemented is wide incentives for, and possibly even subsidies, technological change. Encouraging technological change through energy policies in particular is of critical importance when addressing climate change. For example, rapid early growth in alternative energy sources like wind and photovoltaic technology largely depends on government efforts to build these markets through subsidies. If the government supports such initiatives, they gain mainstream popularity and encourage further private investments, oftentimes above and beyond what the policy provides. On the other hand, if policy measures are delayed, public acceptance will likely be delayed as well. If the world decided to defer implementation of the Kyoto Protocol for another twenty years, for instance, it is likely that private and government research, development, and demonstration of carbon-efficient technologies would drop rather than increase.

Considering the overwhelming complexity and associated political controversy of climate change, there are three questions that should always be asked kept in mind:

1) What can happen?

2) What are the odds it will happen?

3) How are the odds determined?

These questions are critical tools of environmental literacy.  The public’s ability to influence the policy and political decisions designed to combat or capitulate to climate change depends on the degree it has achieved a fluent familiarity with basic environmental concepts.