It is often said these days that we have wasted some thirty years since the end of the cold war when the door opened for much more energetic measures to tackle climate change and avert environmental disaster. Or the time frame is pushed further back to 1972 when the Stockholm Conference on the Human Environment produced its wide-ranging 26-point Declaration  -- the last point, we should notice, was that "weapons of mass destruction must be eliminated". But it is worth going back even further to the 1949 conferences which are now largely forgotten or dismissed in a few lines, (with the notable exception of the journalist and UN historian Linda Melvern whose book The Ultimate Crime: Who Betrayed the UN and Why, 1995, still stands on its own). Could the understanding expressed then of the human potential to wreck our own environment have been taken further, and why did this not happen? Was it just too early to grasp the dimensions of the problem -- and some aspects of it still lay in the future anyway (the sources of greenhouse gases were fewer and, to give an obvious example, there were no plastic bags!) Was it our propensity to look on the bright side, to insist on human perfectibility and believe that technical solutions can always be found? Or was it that the need for post-war reconstruction and to tackle the immediate challenges of poverty and under-development took precedence?  All three factors were in play, but we should not overlook the wider context of a renewed arms race, the diversion of peaceful technological research into military paths, and the intrusion of cold war politics into the scientific community.

One of the most outspoken voices at both conferences was the US conservationist Henry Fairfield Osborn, Jr, who had just published Our Plundered Planet (1948), a fierce critique of humanity’s poor stewardship of the earth’s resources. In that book he had warned that "parts of the earth, once living and productive, have [already] died at the hand of man. Others are now dying". The greatest danger, he told the UNESCO conference, was that technological progress had blinded human eyes to our "essential dependence upon nature". The British delegate was also outspoken: If humanity is to survive, he said, it must "live in harmony with the human principles of ecology. Otherwise the species will die out". And a UN official, the senior economist Alfred Van Tassel, was a driving force behind the parallel Conservation conference, in which seven hundred international scientists discussed deforestation and its effects on drainage and soil erosion, the problems involved with the control of water pollution, the possibilities of hydro-power and the conservation of marine life, and proposed ways of achieving more sustainable and equitable growth.

Yet Van Tassel soon fell foul of the McCarthyite purge along with many other UN officials accused of usually imaginary connection with communism. UNESCO itself became a target of hostility from the American Right, especially for its statements on peace, race and human rights, and had to proceed with caution. And the 1949 conferences were boycotted by the Soviet bloc -- the bloc would also stay away from the 1972 Stockholm conference. The malign doctrines of cold war crippled international cooperation 70 years ago: it must not happen again.