The effects of global warming over the coming decades will be modified by shorter-term climate variability. Finding ways to incorporate these variations will give us a better grip on what kind of climate change to expect.

Studies suggest that tropical cyclones are becoming more powerful with the most dramatic increase in the North Atlantic. The increase is correlated with an increase in ocean temperature. A debate concerns the nature of these increases with some studies attributing them to natural climate fluctuations, and others suggesting climate change related to anthropogenic increases in radiative forcing from greenhouse gases.

The Earth's climate is changing because the composition of our atmosphere is being altered, primarily as a consequence of human activity. We are now also experiencing a non-cyclical rise in the global temperature caused by the accumulation of the so-called "greenhouse gases"--carbon dioxide, methane, nitrous oxide and others.

Any serious attempt to deal with climate change must involve transport. Transport accounts for 13% of all world greenhouse gas (GHG) emissions, though this figure takes into account CO2 sources other than fuel combustion, such as forestry, land-use and biomass burning. A look at CO2 emissions from fuel combustion only shows the transport sector accounts for about 23% worldwide and about 30% in the OECD area.

Tropospheric ozone contributes significantly to human-induced greenhouse warming. Calculations from satellite measurements of spectral radiance suggest that ozone in the upper troposphere caused an average reduction in clear-sky outgoing long-wave radiation over the oceans of 0.480.14 W m- 2 for the year 2006 between 45