Atmospheric CO2

Parts per million

420

400

380

360

340

320

300

1960

1970

1980

1990

2000

2010

2020

Parts per million

420

400

380

360

340

320

300

1960

1970

1980

1990

2000

2010

2020

Guardian graphic. Source: RF Keeling et al, Scripps Institution of Oceanography