I presented the UN data for CO2 emissions equivalent in my environmental economics class on Friday. One student wondered (!*) what the ratio of CO2 equivalent to GDP looked like. Here is the chart with the Gg CO2 equivalents divided by real GDP (in millions) for the U.S. (click on the thumbnail for a bigger image):
Despite all the jokes and sarcasm and biases and cynicism, it appears that the CO2 intensity of GDP has been declining. The annual declines have averaged about 1.9%: -2.48 in 1998, -2.83 in 1999, -0.2 in 2000, -3.18 in 2001, -0.73 in 2002 and -1.98 in 2003.
Update: Could this be evidence of technological innovation?
*Note: I joke, actually, it has been a good class.
In response to some comments:
Update #2: The reduction in CO2/GDP could be due to the increase in the ratio of services to manufacturing in the U.S. economy.
Update #3: Given the current trends in GDP and CO2/GDP, CO2 would begin to fall in 2014 and fall back to 1990 levels in 2018. No doubt, current trends won't continue as all of the low hanging fruit is picked and diminishing efficiency returns set in.
Here is the data:
| Year | GDP (millions) | CO2 | CO2/GDP |
| 1990 | 7112.5 | 5,046,059 | 709.46 |
| 1997 | 8703.5 | 5,747,512 | 660.37 |
| 1998 | 9066.9 | 5,838,752 | 643.96 |
| 1999 | 9470.3 | 5,926,125 | 625.76 |
| 2000 | 9817 | 6,130,768 | 624.51 |
| 2001 | 9890.7 | 5,980,065 | 604.61 |
| 2002 | 10048.8 | 6,031,568 | 600.23 |
| 2003 | 10320.6 | 6,072,181 | 588.36 |
| 2004 | 10650.47 | 6,121,192 | 574.73 |
| 2005 | 10908.88 | 6,143,224 | 563.14 |
| 2006 | 11167.29 | 6,159,263 | 551.54 |
| 2007 | 11425.7 | 6,169,310 | 539.95 |
| 2008 | 11684.11 | 6,173,365 | 528.36 |
| 2009 | 11942.53 | 6,171,427 | 516.76 |
| 2010 | 12200.94 | 6,163,497 | 505.17 |
| 2011 | 12459.35 | 6,149,574 | 493.57 |
| 2012 | 12717.76 | 6,129,659 | 481.98 |
| 2013 | 12976.17 | 6,103,751 | 470.38 |
| 2014 | 13234.58 | 6,071,851 | 458.79 |
| 2015 | 13492.99 | 6,033,959 | 447.19 |
| 2016 | 13751.4 | 5,990,074 | 435.60 |
| 2017 | 14009.81 | 5,940,197 | 424.00 |
| 2018 | 14268.22 | 5,884,328 | 412.41 |
| 2019 | 14526.63 | 5,822,466 | 400.81 |
| 2020 | 14785.04 | 5,754,611 | 389.22 |
| 2021 | 15043.45 | 5,680,764 | 377.62 |
| 2022 | 15301.86 | 5,600,925 | 366.03 |
| 2023 | 15560.28 | 5,515,094 | 354.43 |
| 2024 | 15818.69 | 5,423,269 | 342.84 |
| 2025 | 16077.1 | 5,325,453 | 331.24 |
| 2026 | 16335.51 | 5,221,644 | 319.65 |
| 2027 | 16593.92 | 5,111,843 | 308.06 |
| 2028 | 16852.33 | 4,996,049 | 296.46 |
