Status & scale
The current status is that Earth's atmosphere has planet warming, Carbon Dioxide (CO2) gas, in excess of approx 115 parts per million (ppm) or approximately 27% above where it ought to be (300 ppm), to have a safe and stable climate. This CO2 and other green house gases are causing an average global warming increase of approximately 1 degree Celsius or 1.8 degrees Fahrenheit. We are currently adding approximately 4.6 ppm of CO2 or approximately 1% to the atmosphere each year.
The scale of the global warming issue is still small enough for us to individually take meaningful climate change actions and draw down CO2 out of the atmosphere at the rate of approx 125 Gigatones (approximately 3.3 Hoover dams or the volume of the Dead Sea) per year over the next 10 years and bring it back down to 300 ppm. We must all individually act immediately or it will become too difficult for us to reverse global warming.
The good news and take home message is that the Net cost of the climate change actions needed to reverse global warming is approximately US$27 trillion over 10 years. The cost of fixing global warming is therefore totally affordable as this is only approximately 3% of the 10 year total global world product.
The live counter below shows the current concentration in parts per million (ppm) of Carbon Dioxide (CO2) in Earth's atmosphere.
To return the atmosphere to a safe Carbon Dioxide concentration we need to stop emitting Carbon Dioxide as quickly as possible and more importantly start to draw down Carbon Dioxide from our atmosphere to a concentration of approximately 300 ppm.
What is the cause of global warming and climate change?
The graph above shows that Carbon Dioxide (CO2) is the greatest volume of gas contributing to the green house gas index and fortunately it is one gas that we have a lot of control over.
CO2 is significant because the graph below from National Centers for Environmental Information (NOAA) shows the close correlation between CO2 and temperature (Note how the dark blue line of CO2 concentration is on top of the light blue line of temperature for the last 800,000 years) ;
How recent are the changes to CO2 Concentrations in our atmosphere?
The graph below shows Carbon Dioxide concentration in our atmosphere as parts per million (ppm) varying between approximately 175 ppm to 300 ppm over the last 800,000 years.
The green box on the right is the last 50 years and shows that the concentration of 407.4 ppm in 2018 is off the "normal" scale for the first time in 800,000 years.
We recently heard in Scientific American that the 2019 reading for atmospheric Carbon Dioxide reached 415 ppm.
This is despite the best efforts of the scientific community, environmental groups and activists, over the last decade or two trying to get governments and industry to meet targets of 350 ppm and 400+ ppm respectively.
The last time the atmospheric CO2 amounts were this high was more than 3 million years ago, when temperature was 2°–3°C (3.6°–5.4°F) higher than during the pre-industrial era, and sea level was 15–25 meters (50–80 feet) higher than today.
The green box we have added on the end of the graph above shows the increase of CO2 in the last 50 years in 2018 to be 407 ppm. This data is shown on the graph below smashing through the 350 ppm and 400 ppm CO2 targets set so far;
What concentration of Carbon Dioxide should we aim for in the atmosphere?
Given over the last 800,000 years earth has been a great place to evolve and live, and given what we know about Carbon Dioxide and temperature and the stability of our climate, it makes sense to get the level of Carbon Dioxide in our atmosphere back down to the highest level from last 800,000 years. In other words we need to aim for 300 ppm atmospheric CO2.
How big is a gigaton of CO2 and what is the relationship to ppm?
What is used to describe the quantify of Carbon Dioxide in the atmosphere is the gigaton = 1 Gt = 1 billion or 1,000,000,000 metric tonnes (approximately 1,000,000 imperial tons)
So how much volume is a gigaton? Imagine 400,000 Olympic sized swimming pools. That’s about a billion metric tonnes of water or 1 gigaton of water read more.
The following graph from informationisbeautiful shows earths Carbon Dioxide budget in terms of gigatons of carbon dioxide;
We found the following discussion on a blog about how to convert a gigaton of CO2 into parts per million (ppm) in the atmosphere;
So every 1 Gt of Carbon Dioxide (CO2) we produce adds about 0.129 ppm CO2 in the atmosphere.
The good news is that for every 1 gigaton of Carbon Dioxide (CO2) we take out of the atmosphere, we can reduce the atmospheric Carbon Dioxide (CO2) by 0.129 ppm.
How can we solve the global warming problem and how long will it take?
Fortunately an organisation called Drawdown.org has researched the top 100 things that can be done with existing technology to draw down the Carbon Dioxide from our atmosphere. If we just do the top 15 things over the next 10 years we can 'draw down' the Carbon Dioxide gas form the atmosphere and store it in other forms in and on the planet see table below;
Note: "Educating girls" is about giving knowledge to women in developing countries to take effective action on climate change. Because women are more efficient at agriculture than men by empowering women in developing countries also reduces Carbon Dioxide emissions and allows them to manage their family planning and population growth. These two things combined could contribute to 120 Gt (CO2) drawdown and is one of the single most significant things we can do!
How much CO2 do we need to draw down to fix global warming?
Let's assume that we can implement the above Drawdown solutions to change the climate in 10 years.
So to reduce atmospheric CO2 down from 415 ppm to 300 ppm we need to reduce atmospheric CO2 by 115 ppm.
To get from ppm to Gigatons of CO2 = 115 ppm x 7.76 Gt CO2 = 892.4 Gt of Carbon Dioxide drawdown needed in total.
Let's also assume that we keep emitting CO2 from oil and coal and other sources at the current rate of approximately 36 Gt CO2 per year. (Note the amount of CO2 emissions may go up for the next few years and we may be able to reduce CO2 emissions in the future, but let's say for the sake of our calculation that the average is 36 Gt per year)
Let's assume if we aim to draw down this amount of CO2 over the next 10 years we need to add to our total amount need to be drawn down, our expected Carbon Dioxide emissions over that time i.e. another 10 x 36 Gt = 360 Gt of Carbon dioxide emissions and this will need to be drawn down over the same period.
Therefore, the grand total CO2 drawdown needed over the next 10 years, with our current CO2 emissions continuing at the same level, to get back to a safe level in our atmosphere of 300 ppm, is approximately 1,252 Gt CO2
That means we only have to draw down 125 Gt CO2 (or 50 million olympic swimming pools) per year over the next 10 years.
We have calculated that this is about 3.3 Hoover dams of CO2 per year see below;
Which is approximately the volume of the Dead Sea (35 cu mi). If you click on the minus sign ie "-" in the bottom right of the map below and then zoom out to space you will see how little this volume is compared to the volume of the oceans for example.
Whats it going to cost to draw down 1,252 Gt CO2?
The Drawdown team have estimated that to implement the solutions to bring CO2 in the atmosphere down to 300 ppm would cost US$131 trillion dollars or US$450 per person per year. However the Net cost ie discounting the cost of not acting and the costs that will be avoided from eg sea level rise and insurance payouts etc is only US$27 trillion.
To put this into perspective, the gross world product (GWP) is the combined gross national product of all the countries in the world and is equal to the total global domestic product (GDP) and for 2019 that is estimated to be US$88 trillion. Over 10 years this is US$880 trillion and therefore the net US$27 trillion cost of reversing climate change, is only approximately 3% of the 10 year global world product total.
The good news and take home message is that the cost of fixing global warming is totally affordable.
If we do not act immediately it could cost us 1,000,000 species and make the planet unliveable as soon as 2100 so this is intangible compared to the financial cost of fixing the problem.