Campaigners for the environment have vowed to form a block on the Stand Up To Racism demonstrations on 18 March.
They made their decision at a landmark conference on climate refugees, which more than 200 people attended, in London last Saturday.
It was organised by the Campaign Against Climate Change trade union group and Friends of the Earth.
Asad Rehman from Friends of the Earth warned of a “dystopian future of walls and fences” if solidarity wasn’t built across the movement.
On average one person has been displaced every second since 2008 by disasters.
These included floods, droughts, storms and typhoons that climate change could intensify.
Slower disasters such as failing crops and rising seas could drive many more people from their homes.
There is no legal recognition for those fleeing the effects of climate change.
Workshops dealt with the legal campaign to win such a “climate refugee” status.
Others emphasised that climate change would increase the numbers of people migrating for other more immediate reasons, such as to avoid poverty or join their relatives.
This adds to the case for defending migrants’ rights more generally too.
The TUC and several unions, including the PCS, CWU, TSSA and UCU, supported the conference.
Other organisations, including Stand Up To Racism, also backed it.
The conference’s organisers now plan to follow up the event with a training day on the climate and refugees.