The hon. Gentleman actually raises an important point. At the beginning of the Command Paper is a chapter about the global trends and the direction. Climate change poses a security threat because it could deliver instability, poverty and problems in other parts of the world that would drive migrant flows and increase friction over precious resource. That is absolutely true.
The hon. Gentleman is also right to point out that one of the ways we are going to tackle our security threats is working together across the whole of Government to deal with them. The direction of travel on climate change will hopefully be set at COP26. Defence will play its part in both trying to solve its own emissions and making sure that it provides stability in some of the poorest countries, such as Sudan, where we recently had people, to make sure that the security threat sometimes delivered by climate change does not boil over and threaten regional stability.