She's right that we are not trying hard enough to get off fossil fuels. Getting off fossil fuels would confer a great many geopolitical advantages to us. First, we'd stop sending billions of dollars to hostile oil states like Saudi Arabia, Iran, Venezuela, and many others who fund global terror and work for our destruction. Second, we'd stop having to militarily intervene all the time to ensure the global energy supply. Third, we could stop polluting the aquifers we need to drink from and use for our agriculture (a huge chunk of our economy and exports). Fourth, the absence of supply shocks would stabilize the price of energy so our industry and citizens could all plan better.
All those things, and more, are good reasons to get rid of fossil fuels. But honestly I'm tired of patsies like Greta and their virtue antics.