Whether global warming / climate change contributes to the deterioration of conditions in Central America is beside the point. The folks there clearly have a hard time of it.I have debated this point about the impact of climate change on Central America with Franky.before.
People can make points with heart-rending, emotional appeals. I am simply cynical of the emphasis on climate change. In the political context because that's really the point of this part of the forum, there is not enough support in the U.S. for taking in more Central American refugees. There is a lot of support for aid missions to help with food insecurity. Anyone involved with church groups know there is a lot of private aid in the region. However if you are a journalist or activist who supports Central American immigration to the U.S. (and many do), the climate change argument would appeal to you.
Another factor for Guatemalan emigration to the U.S. is the network effect. We have had a steady increase in Guatemalan emigration for forty years. Many Guatemalans likely know immigrants in the U.S.
I suspect that most refugee claimants from that area do not meet the legal test for a successful refugee claim, as this has to be based on "persecution" in your home country and not just living in an awful place where your kids starve to death. But I believe the developed world falls down badly in how it treats those in less favoured parts of the world - be it Iraq, Syria or Central America.
There should be immigration quotas from these countries to take some of the burden. But we both know that this will never happen and the real reason is racism.