claim: This means the jet stream meanders more, with big loops bringing warm air to the frozen north and cold air into warmer southern climes.”
evidence: In it, the IUGG concurs with the "comprehensive and widely accepted and endorsed scientific assessments carried out by the Intergovernmental Panel on Climate Change and regional and national bodies, which have firmly established, on the basis of scientific evidence, that human activities are the primary cause of recent climate change".