Southern Ocean warming due to human influence

GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L19701, doi:10.1029/2006GL027247, 2006

John C. Fyfe

Canadian Centre for Climate Modelling and Analysis, Environment Canada, Victoria, British Columbia, Canada

Abstract

I show that the latest series of climate models reproduce the observed mid-depth Southern Ocean warming since the 1950s if they include time-varying changes in anthropogenic greenhouse gases, sulphate aerosols and volcanic aerosols in the Earth's atmosphere. The remarkable agreement between observations and state-of-the art climate models suggests significant human influence on Southern Ocean temperatures. I also show that climate models that do not include volcanic aerosols produce mid-depth Southern Ocean warming that is nearly double that produced by climate models that do include volcanic aerosols. This implies that the full effect of human-induced warming of the Southern Ocean may yet to be realized.

Received 15 June 2006; accepted 5 September 2006; published 4 October 2006.

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Minimum Wages & Employment

Minimum Wages and Employment: A Case Study of the Fast-Food Industry in New Jersey and Pennsylvania

David Card; Alan B. Krueger

The American Economic Review, Vol. 84, No. 4. (Sep., 1994), pp. 772-793.

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Abstract
On April 1, 1992, New Jersey's minimum wage rose from $4.25 to $5.05 per hour. To evaluate the impact of the law we surveyed 410 fast-food restaurants in New Jersey and eastern Pennsylvania before and after the rise. Comparisons of employment growth at stores in New Jersey and Pennsylvania (where the minimum wage was constant) provide simple estimates of the effect of the higher minimum wage. We also compare employment changes at stores in New Jersey that were initially paying high wages (above $5) to the changes at lower-wage stores. We find no indication that the rise in the minimum wage reduced employment.

Follow-up

Minimum Wages and Employment: A Case Study of the Fast-Food Industry in New Jersey and Pennsylvania: Comment

David Neumark; William Wascher

The American Economic Review, Vol. 90, No. 5. (Dec., 2000), pp. 1362-1396.

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Minimum Wages and Employment: A Case Study of the Fast-Food Industry in New Jersey and Pennsylvania: Reply

David Card; Alan B. Krueger

The American Economic Review, Vol. 90, No. 5. (Dec., 2000), pp. 1397-1420.

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