Environmental Science: Climate Models and Prediction
Using evidence, scenarios, and uncertainty to understand future climate
Environmental Science: Climate Models and Prediction
Using evidence, scenarios, and uncertainty to understand future climate
Environmental Science - Grade 9-12
- 1
Describe two major types of data that scientists use as inputs for climate models.
Think about information from the atmosphere, oceans, land, ice, and Sun.
Scientists use data such as atmospheric greenhouse gas concentrations, ocean temperatures, solar radiation, land cover, ice cover, and aerosol levels. These inputs help the model represent the major factors that affect Earth's climate system. - 2
A climate model divides Earth into grid cells. Explain why using smaller grid cells can improve a model, and describe one drawback of using smaller grid cells.
Smaller grid cells can improve a model because they represent local climate features more precisely, such as mountains, coastlines, and storm patterns. A drawback is that smaller grid cells require much more computing power and time. - 3
Explain the difference between a climate prediction and a weather forecast.
Compare a single day with a 30-year average.
A weather forecast estimates short-term conditions such as tomorrow's temperature or precipitation. A climate prediction describes long-term patterns and averages, such as likely temperature trends over decades. - 4
A model estimates that global average temperature will rise by 2.4 degrees Celsius by 2100 under a high-emissions scenario and 1.3 degrees Celsius under a low-emissions scenario. Calculate the difference between the two projections and explain what it means.
The difference is 1.1 degrees Celsius because 2.4 minus 1.3 equals 1.1. This means the high-emissions pathway is projected to cause substantially more warming than the low-emissions pathway. - 5
In climate science, explain why future greenhouse gas emissions are often described with scenarios instead of one guaranteed prediction.
Focus on decisions people and governments have not made yet.
Future greenhouse gas emissions depend on human choices about energy use, transportation, land use, technology, and policy. Because those choices are uncertain, scientists use scenarios to compare possible futures rather than claiming that one future is guaranteed. - 6
A graph shows global temperature from 1900 to 2020. The model run that includes both natural factors and human-caused greenhouse gases closely matches the observed warming, while the model run with only natural factors stays nearly flat after 1950. What conclusion is supported by this comparison?
The comparison supports the conclusion that human-caused greenhouse gas emissions are needed to explain most of the observed warming since about 1950. Natural factors alone do not match the observed temperature trend. - 7
Define climate feedback and give one example of a positive climate feedback.
Positive feedback strengthens the original change.
A climate feedback is a process that changes the original warming or cooling effect. One positive feedback is ice-albedo feedback, in which warming melts reflective ice, darker land or ocean absorbs more sunlight, and additional warming occurs. - 8
Aerosols from volcanic eruptions can reflect sunlight back into space. Predict how a major volcanic eruption might affect global average temperature for a short time, and explain why.
A major volcanic eruption may temporarily lower global average temperature because aerosols reflect some incoming sunlight back into space. With less solar energy reaching the surface, short-term cooling can occur. - 9
Climate models are often tested by running them on past climate conditions and comparing the results to historical observations. Explain why this is useful.
Scientists can compare the model output with real measurements from the past.
This is useful because it shows whether the model can reproduce climate patterns that are already known. If a model matches past observations reasonably well, scientists have more confidence in its ability to project future trends. - 10
A model ensemble uses 30 different model runs. Twenty-six runs show warming between 1.8 and 2.6 degrees Celsius by 2050, while four runs show warming outside that range. Explain why scientists use an ensemble instead of relying on one model run.
Scientists use an ensemble because different model runs can represent uncertainty in starting conditions, model design, and climate processes. An ensemble shows the range of likely outcomes and helps identify patterns that are consistent across many runs. - 11
Use the data table: Scenario A has projected 2100 CO2 concentration of 450 ppm and projected warming of 1.6 degrees Celsius. Scenario B has projected 2100 CO2 concentration of 700 ppm and projected warming of 3.2 degrees Celsius. Identify the relationship shown by the data.
Compare both the CO2 values and the warming values.
The data show that higher projected CO2 concentration is associated with greater projected warming. Scenario B has both a higher CO2 concentration and a higher temperature increase than Scenario A. - 12
Explain why regional climate predictions, such as rainfall in one city, are often more uncertain than global average temperature predictions.
Regional climate predictions are often more uncertain because local conditions are affected by many small-scale factors, including topography, ocean currents, land cover, and storm tracks. Global averages smooth out many local variations, making broad temperature trends easier to estimate. - 13
A coastal city uses climate model projections to plan for sea level rise. List two decisions the city might make using these projections.
Think about flooding, buildings, roads, and emergency planning.
The city might decide to raise roads, improve drainage systems, build or strengthen seawalls, limit construction in flood-prone areas, or update emergency evacuation plans. These decisions use model projections to reduce future risk. - 14
A student says, "Climate models cannot be trusted because they do not predict the exact temperature on every future day." Write a response that corrects this misunderstanding.
Climate models are not designed to predict the exact weather on every future day. They are designed to project long-term climate patterns, averages, and trends, such as warming over decades or changes in precipitation risk. - 15
Create a short claim supported by evidence: Climate models are useful for decision-making even though they include uncertainty.
Include both the value of the model and the reason uncertainty does not make it useless.
Climate models are useful because they show likely future trends under different emissions scenarios, even though exact outcomes are uncertain. For example, if many models project more heat waves under high emissions, communities can use that evidence to prepare public health plans and reduce risk.