In Bad Analysis, Bad Policies it was noted that confusing weather with climate for political advantage was being refuted by science and history. Floods, droughts and storms vary cyclically over the decades and short term views confuse these cycles for trends. See Heavy Weather for information about Atlantic storms, Evidence To Suit Every Agenda for information about Pacific tropical storms, and Uphill, Both Ways for information about Alaskan weather changes.

The effects of cosmic rays on low level cloud formation which increase planetary albedo and cool the planet are noted in the Vezier/Shaviz paper widely discussed recently on many blogs. They also note the effects of solar wind in diminishing cosmic ray bombardment. The combined effects of cosmic ray fluctuations due to movement through the spiral arms of the galaxy and fluctuations in solar wind due to sun output cycles were found to correlate with planetary climate better than changes in CO2 and explain some conditions not explained by CO2 variation. Solar output increases directly increase planetary heat but also diminish cosmic ray bombardment due to increased solar wind and so lower albedo from low level cloud formations.

The land use changes discussed in posts linked above not only increase the damages and costs of storms they also affect planetary albedo and cloud formation. A Goddard Space Flight Center story about a paper published in Philosophical Transactions of the Royal Society of London discusses these effects.

Land surface changes, like urban sprawl, deforestation and reforestation, and agricultural and irrigation practices strongly affect regional surface temperatures, precipitation and larger-scale atmospheric circulation. The study argues that human-caused land surface changes in places like North America, Europe, and southeast Asia, redistribute heat regionally and globally within the atmosphere and may actually have a greater impact on climate than that due to anthropogenic greenhouse gases combined.

"Our work suggests that the impacts of human-caused landcover changes on climate are at least as important, and quite possibly more important than those of carbon dioxide," said Roger Pielke, Sr., an atmospheric scientist at Colorado State University, Fort Collins, Colo., and lead author of the study. "Through landcover changes over the last 300 years, we may have already altered the climate more than would occur associated with the radiative effect of a doubling of carbon dioxide." If carbon dioxide (CO2) emissions continue at current rates, atmospheric CO2 concentrations are expected to double by 2050. Land surface changes will also continue to occur.

Indeed they will continue. As population grows half again as large and food production doubles by 2050 much more land will be developed for urban and agricultural use. The ways this will affect planetary albedo are complex.

Types of land surface strongly influence how the Sun's energy is distributed back to the atmosphere. [albedo] For example, if a rainforest is removed and replaced with crops, there is less transpiration, or evaporation of water from leaves. Less transpiration leads to warmer temperatures in that area. On the other hand, if farmland is irrigated, more water is transpired and also evaporated from moist soils, which cools and moistens the atmosphere, and can affect precipitation and cloudiness.

Similarly, forests may influence the climate in more complicated ways than previously thought. For example, in regions with heavy snowfall, reforestation or afforestation would cause the land to reflect less sunlight, and more heat would be absorbed, resulting in a net warming effect despite the removal of CO2 from the atmosphere through photosynthesis during the growing season. Further, reforestation could increase transpiration in an area, putting more water vapor in the air. Water vapor in the troposphere is the biggest contributor to greenhouse gas warming.

Focusing on CO2 and other GHGs such as methane from anthropogenic sources is not just simplistic, it is wrong. Humans have changed the Earth in many ways in the past 300 years. Increased emissions are not the whole story and may turn out to be only a small part of the story. Climate change may be mainly a consequence of solar and galactic changes we have no way to influence. It is foolish to spend all our energy and resources on a single factor, and foolish to spend them before we have useful understanding of the systems involved.

Continuing with the actions being taken at present to reduce emissions for near term objectives of improved air quality and less dependence on finite stocks of fossil fuels makes more sense. Continuing current actions to use existing urban and agricultural land more productively while preserving rural and wilderness lands makes more sense. Continuing current actions to make better use of surface and ground waters makes more sense. Increasing research activity in all of these areas to develop better methods and materials makes sense. Reallocating some of the massive resources and energies being spent on GHG research to other facets of anthropogenic change makes sense.