evidence: CLIMATEWIRE | The Arctic could see ice-free summers as early as the 2030s, scientists say. That’s as much as a decade earlier than previous studies have suggested. [...] The researchers then compared these observations with computer model simulations of Arctic sea ice declines over the same period. The use of simulations allowed the scientists to investigate the influences of individual factors including greenhouse gas emissions, other forms of air pollution and natural climate cycles on Arctic melting. [...] Still, scientists warn that the planet is likely to experience stronger climate consequences as Arctic sea ice dwindles. Bright, shiny sea ice helps reflect sunlight away from the planet. As it disappears, the Arctic warms even faster.