By closing the door to migrants we are denying vulnerable people a way to adapt to climate change - and choking off a powerful form of climate adaptation funding.
International Refugee Day last weekend marked the end of a week of tragedy. A Roma teenager beaten to within an inch of his life, and a woman stabbed to death in Essex for being a Muslim.
The UN Refugee agency announced that Refugee numbers are now the highest they've been since World War II.
The rise of the right in European politics is a signal for the Green movement to stick to its current positive stance on immigration. Not swerve to the right in pursuit of support from UKIP.
There are good reasons that greens of all shades should support more open borders - and one of these is climate change.
Across the world millions of people are using migration as a way of adapting to changing climates. Migration is even creating a powerful form of home-grown adaptation funding.
Migration as climate adaptation
Water stress, drought and desertification are affecting millions of agricultural livelihoods. As climate change forces people into poverty, migration becomes a way of adapting.
This is isn't a distant scenario. Take this testimony from Miguel, a farmer from Mexico:
"My grandfather, father and I have worked these lands. But times have changed ... The rain is coming later now, so that we produce less. The only solution is to go away, at least for a while. Each year I'm working for 3 to 5 months in Wyoming. That's my main source of income. But leaving my village forever? No. I was raised here and here I will stay."
The possibility of working overseas for part of the year keeps his family further from the poverty line.
India - climate change forces seasonal migration
In Chhattisgarh State, India, altered rainfall patterns have reduced crop yields. This creates extreme seasonal unemployment.
Farming is still viable, but it can't employ everyone it used to, all year. People have started migrating seasonally to cities to find work. This is how they are adapting to climate change.
Having some people working away from home strengthens communities against climate change. It means fewer people affected by the drought or water stress. There are fewer mouths to feed at home. People working away often send money home.
This money - remittances - helps insulate the family against environmental and economic shocks. Some communities even pool remittance money and spend it on local climate adaptation projects.
This extra money means communities can improve irrigation and water storage. Some invest in practices that make their agriculture more resilient to climate change.
Making it legal
Much of this migration happens internally. People tend to move from rural areas to cities within their own country. But like, Miguel, some people cross borders to find work. If they can make that move legally, this is far better.
By closing the door to migrants we are denying vulnerable people a way to adapt to climate change - and choking off a powerful form of climate adaptation funding.
Migrating as a way of coping with climate change is not always desirable, let alone popular with the communities who face it. But when people do not have a legal option to migrate they are trapped, as this testimony from Kiribati, in the Pacific shows:
"The majority of I-Kiribati have no wish to live in another country but mounting evidence suggests that we may soon have little choice. Therefore migration may become the key part of the way we are forced to 'adapt'.
"But, there's a problem. Unlike our neighbours Tuvalu ... we have no significant or sympathetic migration relationship or policy with any country." Linda Uan, Kiribati
Migrating comes with risks: exploitation, trafficking, violence. The option to migrate legally reduces these risks. Crossings borders illegally forces people to deal with exploitative bosses and landlords. They are also denied health care.
Violence and intimidation go unreported as going the police is impossible. This is why Greens must support new legal ways for people to migrate as a way of adapting to climate change.
Clear evidence
The latest assessment from the IPCC confirms migration may become a way of people adapt. It also states that migration will become a way for people to avoid forced displacement.
When the impacts of climate change are severe and sustained people move in distress, with no choice about where and when the go. They often end up in camps. Climate change impacts often mix with conflict to trap people in endless cycles of displacement.
Researchers recorded this testimony from an Eritrean man in the My Ayni refugee camp, Ethiopia:
"The weather has become odder and odder. There used to be floods but today there are no floods. People suffer from famine during the droughts. If there is an absence of rain, nobody can do anything - it is a decision of God."
The IPCC argues it's better for people to migrate, while they still have options, than wait and end up in situations like this. Creating options for people to migrate out of harms way is far better than staying put and being displaced later. The authors state:
"Expanding opportunities for mobility can reduce vulnerability for such populations. Changes in migration patterns can be responses to both extreme weather events and longer-term climate variability and change, and migration can also be an effective adaptation strategy."
Free and open borders
By closing the door to migrants we are denying vulnerable people a way to adapt to climate change - and choking off a powerful form of climate adaptation funding.
By restricting migration we are also trapping people in dangerous places. They may eventually suffer displacement or even death.
Alex Randall works for COIN. He runs the Climate Change and Migration Coalition, a network of refugee and migration NGOs with a shared concern about climate change.
Alex formerly worked at the Centre for Alternative Technology. He also worked for the Government of Kiribati delegation to the climate change negotiations in Copenhagen. In 2007 Alex founded the spoof offsetting company CheatNeutral.