# Can a person's individual carbon emissions become negative over their lifetime?

Imagine that a person's individual carbon emissions were logged and accounted for in a ledger over an entire lifetime. If that person could perform certain actions to subtract from their carbon emissions in this ledger, what might these actions be? Via such actions, would it be possible to end up with a carbon negative final total at death, assuming that person continues to indulge in all the activities that currently contribute to global climate change (e.g. eating red meat, using fossil fuels)?

For example, is there a rough number of trees that would need to be planted to 'pay' for these emissions in the ledger over an entire lifetime, and then some (assuming average life expectancy of person living in 1st world country)?

Edit: I understand such a question is necessarily vague due to the sheer number of variables at play. As such, I wouldn't be looking at exact numbers, rather some kind of scale. That is, I would be interested to hear whether something needs to be done hundred's, thousands, or tens of thousands of times, etc. In regards to the individual, let's assume a 'typical' person who lives in Australia (from the Census) and is "married and lives in a couple family with two children" and "lives in a house with three bedrooms and two motor vehicles". Feel free to make any other assumptions, and if possible, skew to the worst-case/heavy use scenario - for example, motor car and/or heating/cooling is used every day, eats red meat every meal, etc.

Aussies emit ~15 tonnes CO2 per capita per year. Current carbon capture and storage technology can bury CO2 for \$40-\$57 per tonne (estimate for early 2020s). So, yes, you could do this for ~\$50,000 .

Underground storage is relatively permanent. As for trees, you could plant one of these,

1,700 tonnes CO2 and lives 3,000 years. With any kind of trees you will need to assure your patch of forest remains treed for millenia. As for the number of trees, I think forested area is a better measure:

Approximative values of the carbon content (tonnes per hectare) for various vegetation types.
Source : IPCC, 2001

You would need tens of hectares.

You'd have to keep your own ledger recording your greenhouse gases emissions over your lifetime; I don't think you'd find anyone mug enough to do it for you. Yes, it would be possible to plant enough trees to more than offset your emissions, provided you had the money and the land. In some countries there is probably enough unsupervised state owned land to solve the land problem. How many trees it would take depends on what kinds you planted: a mountain ash or hawthorn would remove far less carbon than a sequoia or redwood, which are about 1,000 times heavier. In American history there was a character called Johnny Appleseed who went around planting apple trees, so we may be sure that he more than offset his emissions by his tree-planting activities.

• The ledger is purely hypothetical, and I wouldn't be seriously asking anyone to actually keep one - it was just to illustrate my question. In terms of tree type, let's say the one that removes the most carbon (i.e. the sequoia or redwood). Could we come up with a ballpark figure of how many could be planted to offset (and then some) an average person's lifetime emissions? You'll have to please keep in mind I know nothing in this area.
– DRVR
Dec 30 '19 at 23:04