Climate change refers to long-term shifts in global temperatures and weather patterns, primarily caused by human activities releasing greenhouse gases (especially burning fossil fuels). Effects include rising temperatures, changing precipitation patterns, more frequent extreme weather events, rising sea levels, and ecosystem disruption. Climate change affects all levels of government: the federal government sets national targets and international commitments, provinces regulate major emission sources and energy policy, and municipalities address local emissions while adapting infrastructure to changing conditions. Municipal climate action includes emission reduction targets, building efficiency requirements, transit investment, and adaptation planning for flooding, heat, and other climate impacts.