Indeed, a warmer atmosphere supports more moisture, so on average we should see a wetter world. But it might be wetter in Canada rather than the Amazon.
That is why looking at the model outputs is useful for trying to access what MAY happen in your area. I live in the Pacific Northwest, and there is reasonable model agreement that this area gets wetter, and also warmer in winters. However, that in itself does not mean life gets better. This area relies on slow snow melt for irrigation during the growing season. It looks like instead of more snow, we might get more rain in the winters. Much of that runs off. IIRC, there is also model agreement that the SE of the USA gets drier (the general region that has been having draught conditions the last few years). Other places like Australia are much harder to call, because their rainfall is more dependent on specific ocean/wind patterns, and it is very difficult to estimate how those patterns (ENSO?) might change. In that particular case there has been one paper I saw which is claiming that changing wind patterns are shifting moist air normally bound for Australia southward, which leads to drying in Australia, and more precip in Antarctica. Unfortunately, the precip would most likely be more useful to humans in Australia. You win some and lose some.
We've had a little taste of it for the last two years in western Washington, getting some huge rainfall (12-18" range) in single storms, causing massive flooding, but it won't contribute to the water supply during the following summer. Happened both earlier this winter, and in Nov the previous winter.
For whatever regional reasons, the Amazon basin looks like it might dry out more. Other areas of the tropics should get wetter. |
