As a disclaimer, I should first say that I haven't read any of these papers in detail and that I therefore can't comment on their validity. I also don't wish to take a pro- or anti-environmentalist stance. I'm strictly neutral. I'm just talking about the nature of research publications.
Many of us in acadaemia are aware of a perceived phenomenon whereby "fashionable" (for want of a better word) topics get published and/or attract research. From a cynical (yet often accurate) perspective, researchers have become adept at framing their research proposals in the context of the topic du jour. I'm not saying the research is bad, just that funding is easier if you mention buzzwords.
My point is that acadaemia goes through cycles of particular interest in certain topics. The funding gets allocated to it and the journals are more likely to publish research relevant to the "fashionable" topic than other research. Now, I'm not saying the research is flawed; just that if you fund research into environmental change, you're probably going to find a lot of environmental change. If tomorrow you decide to massively fund research into extraterrestrial life, you will see a surge of papers in high-impact journals about that very subject. The environmental change hasn't gone away, it's just that fewer people are trying to publish data about it.
Perhaps for that reason we shouldn't be impressed by the sheer volume of research or the perceived quality of the publishing journals. We shouldn't panic because the number of papers on the subject has increased by several orders of magnitude in recent years. We should get a clear picture of what is going on, ignoring the funding bias, and once we have analysed the data from a balanced perspective and we see that it spells certain doom for all of us, then we can panic. ;)