three times larger than the precipitation over the Atlantic Ocean at the same latitude. Note the logarithmic scale on the vertical axis: "1" means that the land/ocean precipitation ratio is equal to e = 2.718, "2" means it is equal to e2 7.4; 0 means that this ratio is unity (equal precipitation on land and the ocean); "-1" means this ratio is 1/e 0.4; and so on. In Fig. b: the Eurasian biotic pump. In winter the forest sleeps, so the ocean wins, and all moisture remains over the ocean and precipitates there. In summer, when trees are active, moisture is taken from the ocean and distributed regularly over seven thousand kilometers. The forest wins! (compare the red and black lines) As a result, precipitation over the ocean in summer is lower than it is in winter, despite the temperature in summer is higher. Finally, in panel (c): an unforested Australia. One can often hear that Australia is so dry because it is situated in the descending branch of the Hadley cell. But this figure shows that such an interpretation does not hold. Both in wet and dry seasons precipitation over Australia is four to six times lower than over the ocean. There is no biotic pump there. Being unforested, oceanic moisture cannot penetrate to the Australian continent irrespective of how much moisture there is over the ocean; during the wet season it precipitates in the coastal zones causing floods. Gradually restoring natural forests in Australia from coast to interior will recover the hydrological cycle on the continent. Click to enlarge.Mongabay: Have there been any significant changes to your biotic pump theory over the last couple years? Victor Gorshkov and Anastassia Makarieva: The physical basis of the biotic pump consists in the statement that winds are driven mostly by condensation-induced pressure gradients rather than by temperature differences (such as warm air rises) as conventionally considered. As we judged from the first reactions to our work, this is the most difficult statement for the meteorological community to accept. Recently we concentrated our efforts on demonstrating the quantitative validity of the proposed mechanism of condensation-induced atmospheric dynamics. We have shown that it quantitatively explains hurricanes and tornadoes, having obtained from theory radial profiles of pressure and velocity that agree well with observations. On the other hand, we criticized some of the existing explanations of the same phenomena arguing that these contain physical errors. A full list of our publications concerning the biotic pump can be found here. Mongabay: Have you seen wider acceptance in the scientific community for your theory? Redwood forest of Russian Gulch State Park in California. Photo by: Rhett A. Butler Victor Gorshkov and Anastassia Makarieva: Generally, judging from the increasing number of citations of our first biotic pump papers, our work is gradually gaining more attention. The biotic pump theory calls on the meteorological community to admit a possibility that an important atmospheric circulation driver has been overlooked. As long as one continues to ignore the role of condensation in driving winds, one will continue to ignore the real role