The plateau in global warming that took place in the 1950’s and 60’s is still not well
understood; however, evidence from several Notre Dame researchers suggest that sunlight-blocking pollution from dirty factories may have played a role, just as natural variability did in ocean circulation.
A. understood; however, evidence from several Notre Dame researchers suggest that sunlight-blocking pollution from dirty factories may have played a role, just as natural variability did in ocean circulation
B. understood; however, evidence from several Notre Dame researchers suggest that sunlight-blocking pollution from dirty factories may have played a role, in the same way that natural variability did in ocean circulation
C. understood, but evidence from several Notre Dame researchers suggest that sunlight-blocking pollution from dirty factories may have played a role, as natural variability did in ocean circulation
D. understood, but evidence from several Notre Dame researchers suggests that sunlight-blocking pollution from dirty factories may have played a role, as did natural variability in ocean circulation
E. understood, but evidence from several Notre Dame researchers suggests that sunlight-blocking pollution from dirty factories may have played a role, as natural variability may have in ocean circulation