Here's my take: A wise person/people don't just live in the present; they are aware of the past and think about the future, including the possible consequences of their actions in the past, present and future. They plan for the future.
The ancient climatological evidence suggests that Earth has been on average much cooler than the present for most of the last several millions years--usually much colder--with occasional warm periods called interglacials--such as the last 10,000 or so years. Based on the earlier cycles, it appears that the current interglacial has already lasted several thousand years longer than average. That is, the system should be headed into the next Ice Age already...In other words, we should already be experiencing conditions much colder and wetter than the Little Ice Age in the 1800s...instead, Earth is warming...
The Earth and its climate is a dynamic, complex, complicated, and chaotic system--such that even small changes in the inputs and conditions can result in tremendous changes overall. But humans have long thought of the Earth as stable, and unchanging...but it is not, and never has been. Humans have been tweaking it for many thousands of years...it has been warmer before (several thousand years ago), but those were different times, with different conditions, and the potential changes that we have helped to cause over the last several thousand years (and especially the last 250 or so) make the future adaptability of the planet questionable.
What is different now?
For one thing, we've converted lots of land from natural ecosystems into farmland, pastureland, and urban areas, which has caused changes in the reflectivity of the surface, and runoff of water, and lots of other changes, while at the same time reducing the biodiversity of the planet and therefore the ecosystem's ability to respond to the changes.
Another thing we've done is release lots of chemicals into the environment through mining, use of chemical fertilizers, the extraction and burning of fossil fuels, etc. Again, the small changes add up--small increases in CO2 and methane in the atmosphere lead to a change in the energy balance, resulting in warming of the planet as a whole. At the same time, CO2, nitrogen oxides and many other chemicals change the chemistry of the atmosphere and our waters, which affect the species that live there, and so on, feedback into the balance of the system...
Another thing we've done, related to the first two, is greatly increase the human population. Just supporting approaching 8 billion people is going to affect the system, just because we have to convert natural ecosystems to raise the food and build the houses and create the clothing for all those people--it makes an impact on the rest of the system...
Wise people recognize that humans are causing at least part of the change we are experiencing...and even if we aren't the primary or only cause, it's in our interest to find out what is driving that change, and to take steps to adapt to it--even to control it if we can. Do you invest for your retirement? Do you buy health insurance in case you get ill? Life insurance to provide for your family in case you die? That's the same kind of reasoning we need in regard to climate change.
Sure, there are lots of potential "bad" things possible in the future, no matter what happens to the climate. And, there will be lots of "good" things as well; for example, a warmer climate in Canada will allow growth of crops that currently cannot be grown there. In some ways, that's a good thing--but the soils there are not very rich, and will require extensive fertilizer and other chemicals...which is not necessarily a good thing, starting with the fact that turning boreal forests and tundra into farmland means destroying natural habitat, driving out natural ecosystems, and further changing the conditions of the system...
What people need to start doing (in my opinion) is to start looking carefully at what they do and why they do it, and what impacts positive and negative it has--and whether or not they need to change those behaviors...and what might be better ways of doing things, with more positive and less negative impacts.
Frankly, I'm not that opposed to causing some global warming, if it keeps us from having glaciers over most of North America and Europe, etc. But runaway global warming--just as runaway global cooling (an ice age)-- would have mostly bad consequences for most of the present and future human population. And, at this point, we don't have enough knowledge about the functioning of the system, or enough control over our activities, to make controlled changes to the system. Basically, we're blindly mucking about with the system we depend on...hoping that everything will work out okay, or that at the last moment we'll discover how to prevent catastrophe...
Sorry, I'll stop ranting now...
