Environmentalism is a belief that the earth that sustains us is being over-exploited and that something active needs to be done about it.
This is a strong belief in the value of nature and the importance of the environment to human well-being. More often than not the belief is strong enough to encourage action.
Advocates speak out, change their lifestyles, and they do things that promote more reasonable use of natural resources - to make our footprint on the earth lighter.
Theirs is a knowing that the environment is important and a perception that the earth is under threat from human interventions.
It is a tough stance.
Especially when much of the world looks like this...
Throughout recorded history there have been champions for the environment. They were often lone voices.
Before planes, trains and automobiles the earth seemed huge, full of unused, often unexplored, wilderness. Claims that this was anything other than a natural resource bounty to be exploited were met with derision.
Talk of resource degradation and lack when all around were impenetrable forest or grassland as far as the eye could see was ludicrous.
If you claimed that the resource might run out, you were crazy or a heretic.
It wasn't until the middle of the last century when human numbers and industrial might had gripped vast tracts of the endless wilderness that environmentalism became a movement. The lone voices became crowds able to shout and protest. The noise was loud enough to be heard and gather a groundswell that influenced public opinion and political decisions.
Subsequent policy change, regulations, and peer pressure has restrained some of our profligacy and pollution. Nowhere is it perfect but environmentalism has had an effect.
If the 7 billion people alive today had been cutting down forests at the rate the 2 billion alive during Victorian times achieved, there would be no forests left, insecticides would have accelerated the sixth mass extinction, and a whole cadre of government ministers around the world would not have their environment portfolios.
Environmentalism is inevitably reactionary.
Part of its attraction is the minority voice. There has to be a cause to fight for and the process falters when the opponent concedes or even begins to agree with you.
So the arrival of environment ministers, pollution controls, environment protection acts, biodiversity conventions, and the sight of logging trucks trundling away from native forests back to work in plantations, has been challenging.
What is there to shout about?
Climate change? especially anthropogenic climate change.
Climate change fits the profile perfectly:
So for a while climate change has become the environmental issue de jour.
There has been shouting, protesting and bending of the political ear. And, so far, government departments have changed their names, awards have been won for documentary films and an international convention enacted.
The rest is history in progress.
But there is a feeling that the urgency has gone.
The public is less engaged than they were. Governments have run from decisions on climate policy in fear that whatever they do will dent economic growth.
The cynic might suggest that it's time for a new cause.
A good one might be climate change adaptation