1. Tectonic Uplift and Climate Change
Molnar & England, 1990; Egholm, 2009
Austin Rains

2. Introduction
Was late Cenozoic uplift responsible for climate change, or was climate change responsible for late Cenozoic uplift?

3. What is Uplift?
Uplift is the vector opposite of gravity and must have a reference frame as well as an object that moves.
In this case, the reference frame is the geoid (Sea level) and the object that moves is the Earth’s surface (rocks, batholiths, anything apart of the Earth’s crust).
Examples: Himalayas, Alps, Appalachians, Southern Alps (New Zealand)

4. How may uplift affect climate?
Increased elevations at temperate latitudes could increase the duration of winter, therefore, increasing the albedo due to increased duration of snow cover.

5. How may Uplift affect CLimate
An increase in elevation of large regions (Himalayas) affects circulation in the atmosphere as predicted by both modeling and observation.

6. How may Uplift affect Climate?
Increased exposure of minerals due to rapid erosion of sediment. Minerals are transported from high elevations that are cold, down to warm, humid elevations. This absorbs more CO2 from the atmosphere, reducing the greenhouse effect.

7. How may climate change affect uplift?
Uplift due to isostasy.
Erosion of sediment creates an isostatic response, uplifting the Earth’s surface.
Climate change increases erosion rate, therefore, increasing the uplift rates.

8. How may climate change affect uplift?
Glaciers are the primary agent for erosion.
They play a much bigger role in denudation than fluvial processes.

9. How may climate change affect uplift?

10. Evidence used to infer recent uplift
Geomorphology
The sharp incisions of rivers into gentle surfaces of late Cenozoic sediment.
The uplift of a surface with respect to the base level of a river increases potential energy and steeper gradients, which leads to more rapid erosion.
Ranges such as the Alps are tens of millions years old, but still experienced erosion that whole time. However, they underwent more rapid erosion more recently due to climate change.

11. Evidence Continued Sedimentation
Accelerated denudation revealed by sediment accumulation far from mountain ranges.
Accumulation rates of sediment in the Pacific, Atlantic, and Indian oceans in the late Cenozoic are four to fivefold in the last 5 million years.
Sediment around the Southern Alps is younger than 2.5 million years, which correlates well with the Pleistocene glaciation.
If tectonic processes stopped, five-sixths of uplift would still occur.
Mass of Cenozoic sediment in the northwestern Gulf of Mexico

12. Evidence Continued Paleobotany
Using taxonomic analyses to determine what elevation a plant fossil grew at.
One can infer the paleoclimate of the environment that the fossil was found at.
Many studies have ignored global climate change. Given that the Earth cooled during the late Cenozoic, this makes it seem as though mountain ranges have uplifted recently.
Based on Paleobatnical data from the Himalayas

13. Appearance of Uplift
Most arguments of late Cenozoic uplift are exaggerated.
Climate change can be very different in different places.
Physical mechanisms linking climate change to uplift should apply most strongly to regions where mean elevation has increased.
Could also operate where the crests of mountain ranges have risen, but less so.

14. Climate change and uplift: chicken and egg?
Assigning the cause of late Cenozoic climate change to late Cenozoic uplift is hypothesis rejected.
Instead, the phenomena used to infer recent uplift are a consequence of climate change.
Gradual cooling over the past 50 million years may still be due to the tectonic uplift of the Himalayas.
Mean elevation, climate change, and the phenomena used to infer uplift are all coupled to one another.
Possible positive feedback loop: Increased weathering/erosion  negative greenhouse effect  cooler climate  Uplift  increased weathering/erosion

15. Climate Change and uplift: Chicken and egg
It’s still hard to confirm that uplift is a result of climate change.
Both climate change and uplift may have occurred at the same time.
Its safer to say that uplift due to climate change varies from region to region.