If we do act now

Currently, in 2014, CO2 levels in our atmosphere are just over 400 ppm. Now, this probably won’t mean a lot to you. Not even when you are told that the safe level of carbon dioxide in the atmosphere is 350 parts per million. This post attempts to give ‘ppm’ some context.

All this excess greenhouse gas will lead to actual warming. Not many people know that the warming effects are delayed. They think climate change is not true, because “It’s not really getting any warmer”.

This data visualization below takes you on the path of global implementation of the most optimistic ‘Act Now’ scenario: 

  • The ending of deforestation
  • A halving of emissions associated with food production
  • Global emissions peaking in 2020 and then falling by 3 per cent a year for a few decades.

If that path is taken we will pump out an extra 3000 Gt of greenhouse gas, making atmospheric concentrations of greenhouse gases rise to 650 ppm, associated with a global temperature rise of 4 to 6°C.

CO2 level in our atmosphere and global temperature rise due to climate change
CO2 level in our atmosphere and global temperature rise due to climate change

The delusional thing about global warming is that actual warming effects are delayed. What does that mean? Think about what happens when you put the heating on in your home. It takes a while for the temperature to rise. The same is happening right now in the atmosphere. Once the oceans and the atmosphere are fully heated up – like the radiators in your home – the temperature will go up. However, once it’s nice and warm, we can’t switch off the sun. Or get rid of the greenhouse gas that traps the heat from the sun. In fact, it will stay there for at least one millennium.

Words of support from Professor of Public Ethics Clive Hamilton:

‘If we do act now’ is a powerful visual representation of the threat posed by global warming and I fervently hope it will catalyse many people to accept that the Earth and its human population faces a very nasty future. That may be a despairing conclusion, but it is based on the best science available. We will not know how to respond properly until we have felt the despair a person experiences when they find the courage to face the truth of what the scientists have been trying to tell us.


1. The world’s most current data for atmospheric CO2 is measured at the Mauna Loa Observatoy in Hawaii.

2. Why 450ppm is dangerous and why 350ppm is safe

3. Kevin Anderson and Alice Bows, ‘Reframing the climate change challenge in light of post-2000 emission trends’, Philosophical Transactions of the Royal Society, Royal Society, 2008. Referred to in ‘Requiem For A Species’ by Clive Hamilton.