The Sierra Club launched a campaign last week to make climate change a serious issue in the 2000 presidential race and to prod Pres. Clinton and other politicians to take action to address the problem. Kicking things off in New Hampshire, the site of the nation’s first primary, the group told residents that climate change has contributed to the region’s wild weather over the past two years, from a serious January 1998 ice storm to this year’s record-setting drought. The group is circulating postcards that citizens can send to Clinton, Vice Pres. Al Gore, and New Hampshire Gov. Jeanne Shaheen (D), calling for higher fuel-economy standards for cars, more energy-efficient appliances, and lower power-plant emissions. The Sierra Club is making an effort across the nation to alert states and regions to the local threats of global warming.