It’s not. Projections say that global gdp will shrink 18% by 2050 because of climate change [1].
[1] https://www.swissre.com/media/press-release/nr-20210422-econ...
[1] https://www.swissre.com/media/press-release/nr-20210422-econ...
I read GP as talking about the positive impact on GDP of rebuilding, and with the intent of pointing out that GDP is a flawed metric.