By Valerie Volcovici WASHINGTON (Reuters) – U.S. Special Climate Envoy John Kerry has nominated one of his senior advisors, Rick Duke – the architect behind an international deal last year to reduce emissions of the greenhouse gas methane – to be his deputy. In a statement to Reuters, Kerry said Duke will play a leading role in implementing U.S. commitments under the Glasgow Climate Pact and encourage other governments to implement emission reduction targets for 2030 that align with the goal of keeping global temperatures from rising beyond 1.5 C. “Rick’s strategic vision has played a critical…