Humans are really bad at understanding numbers, especially very large or very small ones. We just don't have the neural ability to intuitively get to grips to them... and some scientists believe that the maximum number we can conceive of without abstraction is 3. That is, a pair plus another. All our other number conceptions require some abstraction, often using groups to develop a sense of higher numbers.

Now we are very good at abstractions, so much so that the notion we can only count up to 3 is laughed at by most people - but have a think. What comes to mind when you consider five people? Likely it is 2 people plus 3 people in a group. But even if you are a savant and believe you can count up to an arbitrary number then you would have to admit to having difficulty in imagining a million people. And it's even harder for more abstraction things such as dollars.

Yuval Noah Harari has a new video out - The Actual Cost of Preventing Climate Breakdown - that tries to put some perspective to the task we have in countering climate change... and it is a surprisingly manageable amount... even if it is still a huge number. When compared with other equally huge numbers it's very possible that we can spend our way out of our problems with some sensible prioritising.

It's quite a heartening video and a call to action. And it's a number that is easy to remember... 2% - though it is a little more complicated than ideal Harari has some thoughts on achieving it.