Climate Change
Monday, November 06, 2006 1:29 PM
Global climate change a.k.a. global warming
Pasted from
In the geological history of the Earth, carbon has been cycling among large reservoirs in the land (including plants and fossil fuels), oceans, and the atmosphere. This natural cycling of CO2 usually takes millions of years to move large amounts from one system to another. Now we are looking at these changes occurring in centuries or even decades. Since the Industrial Revolution in the 19th century, carbon dioxide in the atmosphere has risen by 30 percent. This follows the increase in burning of fossil fuels that began with the rise of industry and transportation.
Pasted from
Rising level of atomospheric CO2
The "Keeling Curve" confirms a steady increase in carbon dioxide levels contributing to the greenhouse effect.
Pasted from
Carbon sequestration What is carbon dioxide sequestration?
In its broadest sense, sequestration is any means that prevents carbon dioxide from entering the atmosphere. Realistically, this is equivalent to the permanent storage of carbon dioxide, independent of the state of the CO2 or the location of the storage. Traditionally, carbon sequestration has referred to the carbon stored in biomass, but the definition has come to include the disposal of carbon dioxide underground or in the ocean, as well.
Aplia Page 1
Pasted from
Pasted from
How do we model climate? Climate models are systems of differential equations derived from the basic laws of physics, fluid motion, and chemistry formulated to be solved on supercomputers. For the solution the planet is covered by a 3-dimensional grid
to which the basic equations are applied and evaluated. At each grid point, e.g. for the atmosphere, the motion of the air (winds), heat transfer (thermodynamics), radiation (solar and terrestrial), moisture content (relative humidity) and surface hydrology (precipitation, evaporation, snow melt and runoff) are calculated as well as the interactions of these processes among neighboring points. The computations are stepped forward in time from seasons to centuries depending on the study.
Pasted from
Sources of GHGs
Aplia Page 2
Signs of climate change
The number of Category 4 and 5 hurricanes has almost doubled in the last 30 years.2
Malaria has spread to higher altitudes in places like the Colombian Andes, 7,000 feet above sea level.3
The flow of ice from glaciers in Greenland has more than doubled over the past decade.4
At least 279 species of plants and animals are already responding to global warming, moving closer to the poles.5
Pasted from
Effects of climate change
Aplia Page 3
Cost of not controlling GHG emissions Damages Adaptation Mitigation of damages Sequestration in biomass Plant trees / Reduce rate of deforestation Stern report on BAU We estimate the total cost over the next two centuries of climate change associated under BAU emissions involves impacts and risks that are equivalent to an average reduction in global per-capita consumption of at least 5%, now and forever. The cost of BAU would increase still further, were the model systematically to take account of: • direct impacts on the environment and human health (sometimes called ‘non-market’ impacts) increases our estimate of the total cost of climate change on this path from 5% to 11% of global per-capita consumption. There are difficult analytical and ethical issues of measurement here. The methods used in this model are fairly conservative in the value they assign to these impacts. • some recent scientific evidence indicates that the climate system may be more responsive to greenhouse-gas emissions than previously thought, for example because of the existence of amplifying feedbacks such as the release of methane and weakening of carbon sinks. Our estimates, based on modelling a limited increase in this responsiveness, indicate that the potential scale of the climate response could increase the cost of climate change on the BAU path from 5% to 7% of global
Aplia Page 4
consumption, or from 11% to 14% if the non-market impacts described above are included. Adaptation In what ways might the allocation of resources change in response to climate change?
Mitigation In what ways might resources be reallocated to offsett the effects of climate change?
Cost of control of GHG emissions Stern report: Emissions have been, and continue to be, driven by economic growth; yet stabilisation of greenhouse-gas concentrations in the atmosphere is feasible and consistent with continued growth. Categories of cost of stabilization of emissions: Opportunity cost of benefits in some regions Abatement costs / Emissions reductions
Aplia Page 5
Sequestration of emissions from the source
Pasted from
Aplia Page 6
Public policy/Collective action
Watson/Hayward interview http://www.eande.tv/main/?date=050405
Aplia Page 7