a high stakes virtual summit has been held amid heightened tensions over ukraine. president biden warned of tighter economic sanctions following a huge buildup of russian military vladimir putin blamed provocative actions by kyiv and nato. leaked footage sparks a row over what appears to be british officials joking about a covid christmas party last year breaching lockdown rules at number 10 downing street. every week at this time we take a look climate change bringing you stories with big implications for our planet s future. this week, we focus on aviation and what the future holds for a global and hugely polluting industry. the world s addiction to flying has been rocked by covid but comes at a huge cost to the environment. it s responsible for 2.5 per cent of global c02 emissions and 3.5 per cent of global warming. before the pandemic, passenger demand increased around 5% a year. while it s expected to take two