Climate Change

What does the Keeling Curve Show?

The CO2 concentration in the atmosphere throughout previous decades

Give me Fluxes

Plant respiration, soil respiration, photosynthesis, plant death, herbivore methane release, harvest.

Give me pools

Plants/crops, Soil, Atmosphere,

What is the photosynthesis equation?

CO2 + H20—> Sugars/glucose + 02

What are the two ways cows produce methane?

1.Through Anaerobic respiration in their digestive system

2. Methanogenesis in their digestive system

Which plants benefit more from increased CO2 levels

C3: Wheat, rice, soy beans

I can photosynthesize faster, lose less water, and suffer less photorespiration. My yield gets greatly increased when there’s increased CO2 levels.

What about C4 plants when increased CO2 levels

C4 crops: such as corn and sugarcane; are much more efficient at concentrating C02 so my benefit from increased CO2 levels is less.

Why is lower C-14 in the atmosphere an indicator of human caused climate change?

C-14 is an unstable isotope, that decays into N-14, it is not found in fossil fuels; because we are burning fossil fuels at such a high rate the level of C-14 in the atmosphere is decreasing.

Why is there less C-13 in Methane and coal than air?

It is a larger isotope compared to 12-C and therefore diffuses through the stomates slower, meaning there is less of it incorporated into plant tissue via photosynthesis. Coal and Methane both mainly originate from plant material.

What is evidence of anthropogenic climate change?

1. Isotopes 13-C & 14-C

2. a.) Think about the fossil fuel burning to explain the decrease in 14-C

   1. Think about coal and methane originating from plant sources, meaning less C-13 in air

3. No other activity, besides human activity, can account for the increase.

When does water diffuse out of the stomate?

When CO2 diffuses into a plant leaf.

Question about that weird graph:

Closed circles = maximum, Open circles = minimum

#’s on the right represent the sample size.