When levels of CO2 (carbon dioxide) first hit 350 parts per million newspapers ran it on the front page.
Now, just over a decade later, we're sitting on the edge of 400 parts per million. And yet the political landscape is full of dramatic pledges to do less, not more.
97 per cent of peer reviewed science papers say global warming is happening, humans are responsible and it's accelerating.
The sceptics who argue against science should be compared to people who used to believe the earth was flat.
Climate change is the most pressing issue of our time. A change of two degrees is all that is needed for our planet to tip into catastrophic climate change but projections show we are headed for a four to six degree change.
We are already seeing the effects of unpredictable weather all around the world - bushfires, droughts, hurricanes, huge storms, floods, unseasonable warm or cold summers and winters. All this is set to escalate if we don't reduce our emissions.
Now, more than ever, we need to demand our leaders take decisive action and introduce some of the initiatives already adopted in other countries.
Germany has developed a plan to shift the country from its reliance on nuclear energy and fossil fuels to renewables that will supply 80 per cent of its energy needs by 2050.
China is building a huge network of trigeneration plants to reduce its reliance on coal. Their 50 gigawatt target is bigger than our entire national electricity market grid.
Trigeneration produces low carbon electricity from natural and renewable gas and carbon free hot water used for heating and cooling.
New York's just released a $20 billion plan to prepare for rising sea levels and hotter summers expected as a result of climate change.
Even the world's largest coal mining company, Coal India, is using renewable energy to reduce its energy bills. The company is installing solar panels and admitted it believes fossil fuels are depleting and that we should examine renewable sources of energy like solar or wind.
At the City of Sydney our community has made it clear that they want us to take action.
We've committed to reducing our city's emissions by 70 per cent (on 2006 levels). We've already cut emissions by 19 per cent since 2006, current projects will reduce them by 29 per cent by 2016.
We've achieved this by making buildings more energy efficient, Australia's largest building-based solar roll out and LED street lighting.
After the most detailed investigation ever undertaken of renewable energy resources in and around Sydney, we now have a draft plan showing how all of central Sydney's electricity, heating and cooling needs could be met from renewable electricity and gases by 2030.
We're moving ahead with plans for low carbon trigeneration networks, starting in Town Hall. While our plans for a precinct at Green Square are on hold, we will keep the development trigen-ready as it progresses.
There are already city-wide trigen networks in New York, Berlin, Seoul and soon in China but our governments have removed an incentive that allows similar precincts here to share power through the electricity grid. This urgently needs to change.
We are taking action because cities are responsible for up to 80 per cent of carbon emissions, which means work to drive down emissions in cities provides the greatest opportunity for deep cuts.
But we cannot do it alone. We need our State and Federal Governments to ignore the flat earth conspirators and take bold action to safeguard the world our children and grandchildren will inherit.
(A version of this article was published in the Daily Telegraph on Friday 21 June).