The Climate Action Center (CAC) employs the latest digital engineering and concurrent design techniques to significantly reduce the risk, cost and time required to run complex sustainability and climate resilience projects. We build reusable digital models representing the solutions that need to be put in place to reduce CO2 emissions and prepare for the impacts of a changing climate on our communities. These models will then join an open-source Digital Repository that other actors can use to accelerate and de-risk the execution of crucial climate projects. We build on over two decades of success within the European Space Agency, which has been using the same digital techniques to undertake high-level designs for space missions.