UNFPA said that there was a disproportionate burden on those women and called for greater equality. Poor women do most of the agricultural work, and are therefore affected by natural disasters that impact on food, energy and water.
A slower population growth would help cut greenhouse gas emissions, it added. The report also suggested family planning, reproductive healthcare and "gender relations" could influence how the world adapts to rising seas, worsening storms and severe droughts.
“There are fundamental questions about how climate change will affect women, men, boys and girls differently around the world, and indeed within nations, and how individual behaviour can undermine or contribute to the global effort to cool down our rapidly warming world,” said UNFPA executive director, Thoraya Ahmed Obaid.
She called for any treaty that might come out of the UN climate change conference in Copenhagen next month to take into account individuals' power to "reverse the warming of the Earth's atmosphere".
Temperatures are predicted to rise by 40C to 60C by 2100, with a "likely catastrophic effect" on the environment, habitats, economies and populations, the report said.
Large scale migration could also be seen, as rising sea levels and droughts prompt people to leave uninhabitable land, and poor people could lose their livelihoods. But women, particularly in poor countries, will be affected differently from men, the UNFPA noted.