Simulation of Global Warming in the Continental United States Using Agent-Based

Modeling

By Marika Lohmus

Purpose What is the relationship

between population and global warming?

More people → more greenhouse gases

More greenhouse gases → higher temperatures

Higher temperatures → less people

Population size

Greenhouse gases

Temperature

Figure 1: Negative Feedback Loop

Purpose Cont.

With a negative feedback loop, there should be an oscillating representation of the temperature and population size which should level off.

When, at what temperature and at what cost?

1st Quarter Work

NetLogo Got elevation

data from previous project

Started Temperature map

Took me most of 1st quarter

Fig 2: Q1 Temperature Map

Fig 3: Elevation Map

2nd Quarter

Concentration: Temperature System

Dynamics Agents

Patches Turtles People Cities

Temperature Map

System Dynamics

Agents

Patches Elevation Temperature Death-rate Birth-rate

Turtles Act as borders Negative

values

People Salary 1/10,000

Cities Median Salary Poverty

percent Name

Patches

Change color as elevation or temperature changes

Color determined by change in average global temperature

Fig 5: Temperature Increase

People

Turtle-like agents Human shape Random number

generated for each – birth rate and death rate per 10,000 people per year

Another random number generated to determine whether the agent will move or not

Looks better – otherwise people stay in one place

Assumption

Total population of the united states = population of all the largest cities

Everyone lives in large cities

Everyone has an equal effect on greenhouse gas output

Total greenhouse gas emissions determined by population size

# Factories increase as population increases

3rd Quarter Projections

People: Will be able to move according to salary What temperature is unreasonable? Will birth-rates change?

Patches: More reasonable elevation changes

Current Results

Fig 7: Temperature Data Fig 8: Population Data

Equilibrium between temperature and

population?