We do not so much change our mind about facts, although we necessarily correct and rearrange them in changing contexts. But we do change our minds about the significance of those facts.
I can remember, as a young woman, first grasping the danger of environmental destruction at a conference in 1968. The context was the intricate interconnection within all living systems, a concept that applied to ecosystems like forests and tide pools and equally well to human communities and to the planet as a whole, the sense of an extraordinary interweaving of life, beautiful and fragile, and threatened by human hubris. It was at that conference also that I first heard of the greenhouse effect, the mechanism that underlies global warming. A few years later, however, I heard of the Gaia Hypothesis (proposed by James Lovelock in 1970), which proposed that the same systemic interconnectivity gives the planet its resilience and a capacity for self correction that might survive human tampering. Some environmentalists welcomed the Gaia hypothesis, while others warned that it might lead to complacency in the face of real and present danger. With each passing year, our knowledge of how things are connected is enriched but the significance of these observations is still debated.
J.B.S. Haldane was asked once what the natural world suggested about the mind of its Creator, and he replied "an inordinate fondness for beetles." This observation also plays differently for different listeners — a delight in diversity, perhaps, as if the Creator might have spent the first sabbath afternoon resting from his work by playfully exploring the possible ramifications of a single idea (beetles make up roughly one fifth of all known species on the planet, some 350,000 of them) — or a humbling (or humiliating?) lack of preoccupation with our own unique kind, which might prove to be a temporary afterthought, survived only by cockroaches.
These two ways of looking at what we observe seem to recur, like the glass half full and the glass half empty. The more we know of the detail of living systems, the more we seem torn between anxiety and denial on the one hand and wonder and delight on the other as we try to understand the significance of our knowledge. Science has radically altered our awareness of the scale and age of the universe, but this changing awareness seems to stimulate humility in some — our planet a tiny speck dominated by flea-like bipeds — and a sort of megalomania in others who see all of this as directed toward us, our species, as its predestined masters. Similarly, the exploration of human diversity in the twentieth century expanded for some the sense of plasticity and variability and for others reinforced the sense of human unity. Even within these divergent emphases, for some the recognition of human unity includes a capacity for mutual recognition and adaptation while for others it suggests innate tendencies toward violence and xenophobia. As we have slowly explored the mechanisms of memory and learning, we have seen examples of (fragile) human communities demoralized by exposure to other cultures and (resilient) examples of extraordinary adaptability. At one moment humans are depicted as potential stewards of the biosphere, at another as a cancer or a dangerous infestation. The growing awareness of a shared and interconnected destiny has a shadow side, the version of globalization that looks primarily for profit.
We are having much the same sort of debate at present between those who see religion primarily as a source of conflict between groups and others who see the world's religions as potentially convergent systems that have knit peoples together and laid the groundwork for contemporary ideas of human rights and civil society. Some believers feel called to treasure and respect the creation, including the many human cultures that have grown within it, while others regard differences of belief as sinful and the world we know as transitory or illusory. Each of the great religions, with different language and different emphases, offers the basis for environmental responsibility and for peaceful coexistence and compassion, but believers differ in what they choose to emphasize, all too many choosing the apocalyptic over the ethical texts. Nevertheless, major shifts have been occurring in the interpretation of information about climate change, most recently within the evangelical Christian community.
My guess is that many people have tilted first one way and then the other over the past fifty years, as we have become increasingly aware of diverse understandings — surprised by accounts of human creativity and adaptation on the one hand, and distressed at the resurgence of ancient quarrels and loss of tolerance and mutual respect. Some people are growing away from irresponsible consumerism while others are having their first taste of affluence. Responses are probably partly based on temperament — generalized optimism vs. pessimism — so the tension will not be resolved by scientific findings. But these responses are also based on the decisions we make, on making up our minds about which interpretations we choose to believe. The world's historic religions deal in different ways with loss and the need for sacrifice, but the materials are there for working together, just as they are there for stoking conflict and competition. We are most likely to survive this century if we decide to approach the choices and potential losses ahead with an awareness of the risks we face but at the same time with an awareness of the natural wonders around us and a determination to deal with each other with respect and faith in the possibility of cooperation and responsibility.