Conserving energy and thus saving money, reducing consumption of unnecessary products and packaging and shifting to a clean-energy economy would likely hurt the bottom line of polluting industries, but would undoubtedly have positive effects for most of us.

The failure of world leaders to act on the critical issue of global warming is often blamed on economic considerations.

We need love, and to ensure love, we need to have full employment, and we need social justice. We need gender equity. We need freedom from hunger. These are our most fundamental needs as social creatures.

I always felt that if someone shot me, it would be great for the environmental movement, because they would make me a martyr. Our biggest fear was our children, because there was a tremendous amount of threat and intimidation, and my wife was terrified that the children might be grabbed or assaulted in some way. That was the real fear.

Humans are distinguished from other species by a massive brain that enables us to imagine a future and influence it by what we do in the present. By using experience, knowledge and insight, our ancestors recognized they could anticipate dangers and opportunities and take steps to exploit advantages and avoid hazards.

Outright bans on plastic bags may not be the best solution, but education and incentives to get people to stop using them are necessary.

We emerged out of nature, and when we die, we return to nature. We need to know there are forces impinging on us that we will never understand or control. We need to have sacred places where we go with respect, not just looking for resources or opportunity.

The human brain had a vast memory storage. It made us curious and very creative. Those were the characteristics that gave us an advantage - curiosity, creativity and memory. And that brain did something very special. It invented an idea called 'the future.'

We must reinvent a future free of blinders so that we can choose from real options.

Over and over, the economy has determined the extent of our response, but how much value does it place on breathable air, drinkable water, edible food and stable weather and climate? Surely the economy is the means to a better future, not an end in itself. Surely it must be subordinate to a rich, diverse ecosphere that sustains all life.

All those hours exploring the great outdoors made me more resilient and confident.

My parents survived the Great Depression and brought me up to live within my means, save some for tomorrow, share and don't be greedy, work hard for the necessities in life knowing that money does not make you better or more important than anyone else. So, extravagance has been bred out of my DNA.

Change is never easy, and it often creates discord, but when people come together for the good of humanity and the Earth, we can accomplish great things.

We can't blame children for occupying themselves with Facebook rather than playing in the mud. Our society doesn't put a priority on connecting with nature. In fact, too often we tell them it's dirty and dangerous.

The medical literature tells us that the most effective ways to reduce the risk of heart disease, cancer, stroke, diabetes, Alzheimer's, and many more problems are through healthy diet and exercise. Our bodies have evolved to move, yet we now use the energy in oil instead of muscles to do our work.

Doing all we can to combat climate change comes with numerous benefits, from reducing pollution and associated health care costs to strengthening and diversifying the economy by shifting to renewable energy, among other measures.

For the sake of our health, our children and grandchildren and even our economic well-being, we must make protecting the planet our top priority.

There are more humans than all of the rabbits on earth. There are more of us than all the wildebeests, than all the rats, than all the mice. We are the most numerous mammal on the planet. But because we're not like rabbits or rats or mice, we have technology, we have a consumptive appetite, we have a global economy.

If America wants to retain its position as a global power, its president must listen to the people and show strong leadership at this turning point in human history.

If we pollute the air, water and soil that keep us alive and well, and destroy the biodiversity that allows natural systems to function, no amount of money will save us.

The truth is, as most of us know, that global warming is real and humans are major contributors, mainly because we wastefully burn fossil fuels.

It doesn't give me any satisfaction to think that my concerns will be validated by my grandchildren's generation. I would love to be wrong in everything. My grandchildren are my stake in the near future, and it's my great hope that they might one day say, 'Grandpa was part of a great movement that helped to turn things around.'

The human brain now holds the key to our future. We have to recall the image of the planet from outer space: a single entity in which air, water, and continents are interconnected. That is our home.

If we want to address global warming, along with the other environmental problems associated with our continued rush to burn our precious fossil fuels as quickly as possible, we must learn to use our resources more wisely, kick our addiction, and quickly start turning to sources of energy that have fewer negative impacts.

From year to year, environmental changes are incremental and often barely register in our lives, but from evolutionary or geological perspectives, what is happening is explosive change.

In the environmental movement, every time you lose a battle it's for good, but our victories always seem to be temporary and we keep fighting them over and over again.

It's not unexpected that shooting massive amounts of water, sand, and chemicals at high pressure into the earth to shatter shale and release natural gas might shake things up. But earthquakes aren't the worst problem with fracking.

Beyond reducing individual use, one of our top priorities must be to move from fossil fuels to energy that has fewer detrimental effects on water supplies and fewer environmental impacts overall.

Over and over, we hear politicians say they can't spend our tax dollars on environmental protection when the economy is so fragile.

We must pay greater attention to keeping our bodies and minds healthy and able to heal. Yet we are making it difficult for our defences to work. We allow things to be sold that should not be called food. Many have no nutritive value and lead to obesity, salt imbalance, and allergies.