The solutions for the problem of global warming already exist. CO2 is by far the most important GHG, contributing the vast majority of the warming. Most CO2 emissions come from transportation, electricity generation, industrial sources, and residential use of natural gas. Phasing out first coal and then gas will take care of electricity and industry, electric cars already exist, and there ought to be affordable alternatives to natural gas for residential heating and cooking. Eliminating coal mining and transitioning away from natural gas as much as possible will deal with the majority of methane emissions, and people are already consuming less beef, meaning emissions from enteric fermentation and manure management are already declining (and which, BTW, is not the biggest cause of global warming, contrary to what I've seen vegan and animal rights activists insinuate).
But the biggest thing we can do to solve the problem is to simply have fewer children. If every couple on Earth restricted themselves to one child until we halved the global population, and only two children after that, that would do a lot. Population growth fuels demand for resources of all kinds, among other things. We need to let go of this idea that growth is good, that populations and economies need to continue growing ad infinitum. Natalist policies in nations with sub-replacement fertility are suicidal outgrowths of that mentality. China may have gone about it the wrong way (typical for authoritarian regimes), but the one-child policy was the right idea in a general sense. We don't need to be encouraging people to have more children. We need to do the opposite. We've mostly taken care of that in the developed world (the so-called "demographic transition" is part of the natural course of fertility rates as nations industrialize), and we ought to be helping developing nations reduce their fertility rates (condoms/birth control and pushing for societal reforms as they pertain to families and the role of women) in anticipation of the day when each of them eventually industrializes.
And as others have pointed out "rare earth" metals aren't that rare. Gold and the platinum group metals are all two orders of magnitude less abundant than even thulium, which is the least abundant rare-earth (except for promethium, which has no stable isotopes).
If you're a gamer, the impact of your hobby is negligible on the environment. The amount of CO2 emitted from the production of electricity to power consoles and PCs is a tiny, tiny portion of all CO2 emissions, as is that from the manufacture and transport of hardware and software. Even in terms of garbage the impact is minimal. I won't go into details here, but I've done the math and even if every physical game and case produced globally this generation was thrown in the garbage it would amount to maybe 0.1% of the garbage the U.S. alone produces every year. Oh, and game discs and cases can be recycled, and it goes without saying that only a tiny percent of games are simply discarded.