In terms of raw volume of water no, sibling comment has done the maths. But there is another interesting effect that's tangentially relevant. Forested areas act

In terms of raw volume of water no, sibling comment has done the maths. But there is another interesting effect that's tangentially relevant. Forested areas act as rainwater sponges. When you get heavy rainfall, if you've got nothing but tarmac or even grass, all that water runs straight off and into the nearest river. Which then bursts its banks and floods everything nearby, making building on floodplains a bloody stupid idea. With forests, though, the depth of the roots means the water can sink more into the ground. It all still ends up in the river eventually, but over a much longer time period. Because the big pulse of water from the rainfall is attenuated, the river has more of a chance to drain away, so you get fewer, and less serious, floods. The net effect is that while we'll lose land to rising sea levels, in some areas there's the opportunity to reclaim land currently too marginal to occupy. Nowhere near the same land area, but it's a worthwhile effect to be aware of where it applies.