Is 28 tonnes of CO2 a year a lot?

28 tonnes of CO2 by group

Percentile is the share of the world's people who emit less than this a year. “1 in X” counts the rarer side: people at or beyond this value above the median, at or under it below. Percentiles are estimated from a normal distribution with mean 4.7 t and SD 2.8 t, which understates the long right tail.

What this means

• Absorbing 28 tonnes takes about 1,260 trees growing for a full year, at the 45 trees per tonne our carbon test uses. The rule of thumb is generous; trees are slow and offsets are a crowded market.
• The closest national average is Australia at 15.1 t. An American averages 14.5 t, an Indian 1.9 t, so 28 tonnes is 14.7 times the Indian figure.
• Country figures are territorial emissions divided by population: power stations, cement works and all, not a household's shopping. A personal calculator counts consumption and misses imports. Neither is precise to the tonne.
• Emissions are skewed, with a long tail of frequent flyers and large houses. A normal curve understates how rare the top end is, so treat this percentile as a floor. The richest 10% of people cause about half of all emissions.

Questions

Is 28 tonnes of CO2 a year a lot?

28 tonnes a year is more than over 99% of the world's people emit, against a global mean of 4.7 tonnes per person. That is the American or Australian average, the heaviest in the table and about three times the world mean.

What is the average carbon footprint per person?

About 4.7 tonnes of CO2 a year worldwide. Australia averages 15.1 t, the United States 14.5 t, Germany 7.9 t, the United Kingdom 5.5 t, Sweden 3.8 t and India 1.9 t (Our World in Data, territorial emissions).

How many trees offset 28 tonnes of CO2?

About 1,260 trees absorbing for a year, at 45 trees per tonne. Put differently, one tree would need 1,260 years. Planting is cheap; the carbon stays out of the air only as long as the trees stand.