Being the canary in the coal mine: New Orleans and global warming

Torbjörn E. Törnqvist

Department of Earth and Environmental SciencesTulane University

Torbjörn Törnqvist

Department of Earth and Environmental Sciences

Coastal Louisiana in a World ofGlobal Change

A Very Brief History of the Greenhouse Effect…

Joseph Fourier (1824)

John Tyndall (1859)

Svante Arrhenius (1896)

http://www.climate-lab-book.ac.uk/files/2016/09/spiral_aug2016.gif

Last Glacial Maximum~21,000 years ago

Global mean temperature:~4˚C lower

Global mean sea level:~135 m lower

Sea-level history, global average

Ice sheet saddle collapse

Predicted Land ChangeFuture Without Action - Year 50, Low Scenario

2017 Coastal Master Plan

Predicted Land ChangeFuture Without Action - Year 50, High Scenario

2017 Coastal Master Plan

12 ± 8 mm yr-1

~35%

~35%

Some Take-Home Messages…

Anthropogenic climate change is old (19th century) science

Some Take-Home Messages…

Anthropogenic climate change is old (19th century) science

Louisiana represents one of the most vulnerable coastal zones in the world, with a present-day rate of relative sea-level rise of 12 ± 8 mm yr-1

Some Take-Home Messages…

Anthropogenic climate change is old (19th century) science

Louisiana represents one of the most vulnerable coastal zones in the world, with a present-day rate of relative sea-level rise of 12 ± 8 mm yr-1

Ice sheets constitute perhaps the world’s largest threat for the future; even with just over 1 °C of warming tipping points may be unavoidable

Some Take-Home Messages…

Anthropogenic climate change is old (19th century) science

Louisiana represents one of the most vulnerable coastal zones in the world, with a present-day rate of relative sea-level rise of 12 ± 8 mm yr-1

Ice sheets constitute perhaps the world’s largest threat for the future; even with just over 1 °C of warming tipping points may be unavoidable

Mitigation remains critical, but we will be increasingly locked into adaptation

Do you think human activity is asignificant contributing factor in

changing mean global temperatures?

Sea-level history, US Gulf Coast