The aftermath of Katrina and Rita gets worse with estimates of 320 million trees in Mississippi and Louisiana killed which amounts to "$2 billion, or 5.5 billion board feet worth of timber". Also, "The die-off, caused initially by wind and later by weeks-long pooling of stagnant water, was so massive that researchers say it will add significantly to the global greenhouse gas buildup -- ultimately putting as much carbon from dying vegetation into the air as the rest of the nation's forests take out in a year of photosynthesis."