James Hansen Climate Quotations

We've driven them out of the range that has existed for the last 1 million years. And the climate has not fully responded to changes that have already occurred.

I think this is a more optimistic assessment of the chances for keeping climate change moderate in the next 50 years, and the way to do that is to focus on stopping the growth of several gases, ... Global Warming in the 21st Century: An Alternative Scenario.

Tipping points are so dangerous because if you pass them, the climate is out of humanity's control: if an ice sheet disintegrates and starts to slide into the ocean there's nothing we can do about that.

We need to send a message to Congress and the president that we want them to take the actions that are needed to preserve climate for young people and future generations and all life on the planet.

After spending three or four years interacting with the Bush administration, I realized they were not taking any actions to deal with climate change. So, I decided to give one talk, and then it snowballed into another talk and eventually to even protesting and getting arrested.

Climate change is analogous to Lincoln and slavery or Churchill and Nazism: it's not the kind of thing where you can compromise.

There is still time to act and avoid a worsening climate, but we are wasting precious time,

We are on the precipice of climate system tipping points beyond which there is no redemption.

The climate system is being pushed hard enough that change will become obvious to the man in the street in the next decade.

The evidence for human-made climate change is overwhelming.

We're running out of time.

...the global surface albedo [surface whiteness] and greenhouse gas changes account for practically the entire global climate change.

Policy decisions on climate change are being deliberated every day by those without full knowledge of the science, and often with intentional misinformation spawned by special interests.

The forcings that drive long-term climate change are not known with an accuracy sufficient to define future climate change.

We have known since the 1800s that carbon dioxide traps heat in the atmosphere. The right amount keeps the climate conducive to human life.

The urgency derives from the nearness of climate tipping points.

As species are exterminated by shifting climate zones, ecosystems can collapse, destroying more species.

I think we have a very brief window of opportunity to deal with climate change... no longer than a decade, at the most.

Coal is the single greatest threat to civilization and all life on our planet.

Cap and trade generates special interests, lobbyists, and trading schemes, yielding non-productive millionaires, all at public expense. The public is fed up with such business. Tax with 100% dividend, in contrast, would spur our economy, while aiding the disadvantaged, the climate, and our national security.

Global warming isn't a prediction. It is happening.

Being at NASA and having the access to both computing capability and satellite observation capability is kind of the ideal research situation to try to understand global climate change.