The six largest banks in the U.S. have until the end of July to show the impact that climate change could have on their operations, according to details of a pilot program the Federal Reserve unveiled this week. Under the review, the institutions are to show the anticipated impact that events such as floods, wildfires, hurricanes, heat waves and droughts could have on their loan portfolios and commercial real estate holdings. A hypothetical scenario focuses on events in the Northeastern U.S.