They can look at previous data and compare it to current data of the climate, from there they can estimate climate change. Example: in 1977on july 23rd the temperature was 28°C. on july 23rd 2017 the temperature was 32°C. the temperature in 40 years the temperature changed by 4°C
"A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another. ... Food webs consist of many interconnected food chains and are more realistic representation of consumption relationships in ecosystems."
The reason for this is because it is closer to water, therefor they have more events that could happen. Also there is a lot of weathering, erosion, and deposition which makes the gulf coast prairies and marshes more susceptible to changes.
I hope this helps!
For the first question, I would say a line graph. And the one about the human heart, I need some more information.
