Man made CO2 measurement

[David H]

The official figure is that man produces 3% of the CO2 in the atmosphere. Since the industrial revolution the total has increased by 30%. I can't handle maths so not sure how these two fit together, but are they saying we've added a cumulative 3% which over 100 or so years has left a little more not reabsorbed by nature, or does it mean something else has been contributing to the increase while man barely makes a difference?

[factor-fiction]

The original percentage figure will be 3.0 ÷ 1.30 = 2.3%

So it has increased from 2.3%

[factor-fiction]

My answer assumes you meant that man's contribution to the total CO₂
level has increased by 30% (three tenths) since the industrial revolution to 3%.

[R1Geezer]

it's the difference between percentage and percentage points. the confusion comes when the base is itself a percentage. so if inflation is 5% and it goes up by 10% then the new figure is 5.5% but sometimes they'll say n the news it's risne by 1% to 6% but what they mean is it's gone up by 1 percentage point.

[jake-the-peg]

David,

What is important is the difference between what goes in and what comes out.

It seems that the planet's ability to absorb Co2 has been exceded

Put (overly ) simply you have a sink that lets out a litre per second and a tap that puts in 0.99 litres per second then you add another tap that puts in 0.03 litres per second.

Soon you have a flooded kitchen.

Not only that buy you have to consider that a lot of out development has affected the planet's ability to absorb CO2 - things like cutting down rainforests etc.

So it's not just that we're putting more in - we've been clogiing up the sink too

[vascop]

Have a look at page 6 of chapter 1 of this book:
http://www.withouthotair.com/

[vascop]

I would recommend this book to anybody interested in sustainable energy and/or climate change. You can buy it as a normal book or download it from the site above, or read it on-line.
It contains almost everything you need to know and more!

[boxtops]

what a good description JTP, overflowing the sink whilst blocking the outlet - I like it, easy to visualise!

[New Judge]

Of course, what jake's analogy did not include was how full the sink was when the excessive input began.

[jake-the-peg]

That's not relevant NJ

If the flow in is less than the capability to drain a stable equilibrium is reached

If not then the equilibrium is lost.

Current research strongly suggests that human activity has pushed us over that equilibrium.

CO2 levels are going up and up to the highest that they've been in over half a million years and 40% up on where they were at the start of the industrial revolution

the action of CO2 is basic science

Really the only contraversial thing now is exactly how the global warming trend will affect the climate and sea levels.