There can be no doubt about which issue is of greater importance for our future, but the “usual suspects” (our politicians and the commentariat) largely divide along the same lines on both. And in each case trade should be a crucial element in the policy mix and the political arguments.
Brexit may be a forgotten issue in twenty years’ time (although it might not be wise to put money on that), but we can guarantee that climate change will still be with us, most likely with ever more serious manifestations in terms of extreme weather and disruptive droughts and floods, but also with less time left to avoid climate catastrophe. We can also guarantee that under these conditions it, or rather the politics of mitigation and adaptation, will be climbing steadily higher on the political agenda.
Increasingly countries making serious attempts to reduce carbon emissions will find it difficult to tolerate the export of jobs in energy intensive sectors to countries that pursue more lax policies. Climate policies will necessarily intrude into trade negotiations.
Brexiters will have many more questions to answer.