The evolution of Theorg lO wags science is changingouPworld. Stephen Bocking HE LAST40 YEARS have shownthat science is essential to how we know, exploit and argue about nature.Scientists haveidentified environmental challenges - from contaminants to climate change - and described their consequences for people and the planet' Demonstrating how far scientific discovery has taken us,consider the factthat many of today's most urgent concerns, and how we discuss them,would have beenunintelligible four decades ago. Along the way, scientists have described nature itself - helping us understand what we valueand seek to protect.But science hasalso beenthe focusof controversy: uncertainassessments of cod, salmon and other resources) or of the impacts of the tar sands and other indus- tries; the unpredictable consequences of GM crops, nanotechnology and other novelties created by science; the twisting of knowledge about climatechange and other hazards.Inthese and other instances, science hasbeen implicated in, and haseven encouraged, political conflict or paralysis. To makesense of this history,I've identifiedand ranked 10 essential devel- opmentsin scientific knowledge (in ascending order of importance). The Canadian and globalenvironments look very different now than they did in 197 I. andthese aresomeof the reasons why. 37:6/ 20\ I Alternativesjournal.ca 25