As scientists meet in Stockholm this week to discuss the launch of the IPCC’s Fifth Assessment Report on the physical science basis for climate change, the general public’s understanding about this important issue is further than ever from reality.

The Yale Project on Climate Change Communication reports that while 97% of scientists think climate change is happening and is caused by humans, only 41% of American citizens agree; a recent YouGov poll put the figure in the United Kingdom at 43%.

Such a disparity often stems from misleading claims by climate change sceptics that the data, by climate scientists’ own admission, contains uncertainties and therefore cannot be relied upon. The result of public and political confusion around climate change is that – at least at a scale commensurate with the problem – no one seems to be doing anything about it. It is, therefore, important to understand what really is uncertain about climate change so that attitudes can be changed and action can be taken.

The uncertainty is not whether or not climate change is happening – it is. Humans have unequivocally changed the climate and continue to do so; the scientific community has known this for decades. The uncertainty is not what the basic consequences will be. Biodiversity loss, more extreme weather events, rising sea levels, mass migration – all of these things are inevitable if we fail to act.

The uncertainty is exactly how great the extent of the change in the climate is going to be. What exactly is going to happen? Where? When? We know there will be undesirable impacts, but in many cases not the extent and timings of those impacts. Climate change deniers seize on this and the scientific language of “uncertainty” to bend political will to maintaining the status quo.

So how do we get greater certainty? The current thinking is that we wait until time has passed and see whether and which models predict the changes accurately. This is likely to take 30-40 years. By the time we get certainty this way, it will be too late.

Fortunately, for those politicians, businesses and individuals that need certainty before they act, there’s a way of giving it to them much more quickly. The answer lies in a proposed European satellite mission called TRUTHS and its US counterpart CLARREO. Both missions are expected to make measurements of the Earth and Sun with unprecedented accuracy. These would feed into climate models, but also would be directly applied to testing climate models, giving us greater confidence about the most likely temperature rise and consequences of climate change three times earlier than we are currently able to do now.

The international community has highlighted the need for such a mission; ESA and NASA are exploring how best to progress. The necessary instruments are designed and available. At present, the major barrier is lack of resources to bring together the technologies on a small satellite platform and launch it into space. But it is a barrier that can be broken.

Do we need more certainty before we act on climate change? Absolutely not. But if greater certainty would support political will to act, we must do everything we can to provide it.

Read more blogs on the environment.

Author: Jane Burston is Head of the Centre for Carbon Measurement at the National Physical Laboratory in the United Kingdom.

Image: An animal skull lies on the ground at an abandoned farm, near the dried up Shiyang river on the outskirts of Minqin town, Gansu province September 20, 2013.