In the slim chance that your question is non-rhetorical:

• Many people do not consider global warming to be a problem. Others think that there is nothing useful to be done about it. Personally I do not consider global warming to be a serious threat; people will adapt fairly easily to temperature changes within the likely ranges. Further, any realistic 'cure' for global warming would almost certainly be worse than the disease. Therefore I do not view climate change activism to be a worthy cause at present, although that could change.
• History and economics both suggest that so-called non-renewable resources are in fact very robust. Mankind has never run out of any non-renewable resource, whereas we have run out of many renewable ones. The fact that a resource has a hypothetical 'renewability' does not necessarily have much impact on the limits to its use. For instance, we need to worry far less about running out of coal than condor eggs. I view most investment in renewable resources as pure boondoggling, and pretty much the opposite of a worthy cause.
• Preventing and relieving humanitarian crises can be a worthy cause in principle. But in practice activism along those lines seems heavily counterproductive. I often wonder how many fewer crises there would be if

So basically, I don't think MIRI is likely to do much good in the world. But I'd much rather donate to them rather than Greenpeace, Solyndra or Oxfam, because at least they're not actively doing harm.