One thing I haven't addressed yet in this blog is climate change. I think it's a huge deal, but I don't have any particular insights about it.
However, one objection sometimes given to more liberal immigration policies is that when immigrants get here, they use more resources than they otherwise would. By improving their lives, they contribute more the strain that developed nations place on the planet. In fact, this is actually an argument to improving the welfare of people in the developing world; sometimes people use it as an excuse for why they don't give much to charities, like those recommended by GiveWell or Giving What we Can.
This obviously a self-serving and hypocritical argument. And no one ever takes it to its logical conclusion, of course, which is that you should murder your entire family. Your family certainly consumes many resources, which contributes to climate change, and they would consume less if you killed them. No one says this, because of course it's ridiculous. (A related, but much more plausible implication, is that you shouldn't have children.) This is because we have obligations to those people who exist, which include refraining from killing them and making their lives better if we can.
Making their lives better can lead to greater abuse to our planet, but if that's your concern (and it should be) we should also advocate for policies that mitigate these concerns. So if we're going to open up our borders to the masses of people who want to immigrate, one thing we should do is open up our skies for the building of taller buildings. Repeal zoning regulations that limit high-density living in cities, so that we can get best use out of our land (and pay lower rent!). High density living demands fewer resources per person, and has many other positive externalities, about which Matt Yglesias wrote a book. Also, tax carbon!
If you think animals are important too, as they are, you should join me in advocating veganism to everyone, including anyone who might be moving here for a better life. That way, increasing the welfare of those in developing nations doesn't have to mean an increase in the slaughter of non-humans.
The fact that there are some problematic consequences to fulfilling our obligations does not necessarily nullify our obligation. It often means we have greater obligations! One thing I never thought I'd have to do is learn some economics. But I've decided to learn some economics because advocating for the right policies is a great way to help people.
Most consequentialists would agree with me on these points, I think. But it seems to me that, even if they're right to agree, they shouldn't be quick to agree. They'd actually have to go through the calculus to see which policies are most likely to be effective, and proceed from there. The calculus, of course, is notoriously difficult, so involves a lot of reasonably hopeful guessing, but in principle it ought to be done.
Because I'm not a consequentialist, I don't have to consider all the possibilities. Most notably, I don't have to consider the option of killing my family, because it would be wrong.