In the past few decades we have been improving our understanding of the weather system and exploring ways to modify it. Over sixty countries have experimented with modifying the weather. The new technology of weather and climate modification will raise important political problems which will demand new responses from the international community. Whether states will be able to establish the cooperative measures necessary to develop and manage new technology depends upon whether there are sufficient incentives to do so. This article analyzes the historical patterns of international cooperation in meteorology, and then plots against several time horizons projected developments and capabilities in weather modification technology and the potential problems emerging from using the technology. It derives a tentative picture of the responsibilities demanded, compares the likely responses with those needed, and assesses whether they will be adequate for the problems projected.