The world’s biggest financier of fossil fuels, JP Morgan, warns clients that without action on climate change there could be “catastrophic” outcomes.

The warning came in a report prepared by two JP Morgan economists, David Mackie and Jessica Murray, which was strikingly candid in its analysis of the consequences of climate change.

“We cannot rule out catastrophic outcomes where human life as we know it is threatened,” they said

The analysis, leaked to the BBC, said carbon emissions in the coming decades “will continue to affect the climate for centuries to come in a way that is likely to be irreversible”.

It added that climate change could affect economic growth, shares, health, and how long people live.

It could put stresses on water, cause famine, and cause people to be displaced or migrate. Climate change could also cause political stress, conflict, and it could hit biodiversity and species survival, the report said.

To mitigate climate change, net carbon emissions need to be cut to zero by 2050. To do this, there needed to be a global tax on carbon, the authors said.

In 2019, the Rainforest Action Network released a study claiming that JP Morgan provided the most fossil fuel firm financing of any bank in the world from 2016 to 2018.