Hawaii's emissions of greenhouse gases actually declined by 22% between 1990 and 1999, but bounced up again in recent years (via EPA).
The downturn appears to have been related to the economic slump during the 1990s, while the return of "good times" is boosting emissions now.
Still, new data from California rank Hawai`i 14th out of 50 states in emissions per capita.
We are also one of only 4 states that have actually reduced CO2 emissions since 1990, along with Delaware, Connecticut and New York.
In 2002 (the latest year EPA provides state-level details) Hawai`i accounted for 18.9 million tons of CO2 equivalents. In 1999, it was 16.7 million tons, and in 1990 it was 21.5 millions tons.
Just over half of these emissions are generated by transportation, and another third come from electricity generation.
I have estimated that emissions from visitor air travel, which are not included in EPA's calculations, could have added another 6.6 million tons in 2005 (based on visitor volume for that year and jet fuel emissions from the mobile combustion spreadsheet at GHG Protocol).
This suggests that efforts to reduce Hawaii's emissions will come up against the air travel conundrum. Surely if our state is going to cut 90% of our emissions (i.e., from 20 million to 2 million), that 6-7 million tons from air travel looms large.