Web Climate Lab

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Which climate policy will the world follow?

The world will do very little to reduce greenhouse gas emissions, allowing them to reach three times current levels by 2100.

The world will delay taking action to reduce greenhouse gas emissions, allowing them to reach nearly twice current levels in 2060 but reducing them to just above current levels by 2100.

The world will take significant action to reduce greenhouse gas emissions, peaking them just above current levels by 2050 and reducing them to less than half of current levels by 2080.

The world will take aggressive action to reduce greenhouse gas emissions, reducing them to zero by 2080.

Tune your model

How strongly does the climate respond to greenhouse gases?

How quickly does the ocean absorb heat from the atmosphere?

Welcome to the Web Climate Lab!

This application is built around a simple climate model, which demonstrates the process used by more sophisticated models to help us understand climate change. Click “Start” for an introduction to the model, or click “Skip” to start using it immediately.

Choose a policy scenario

First, choose which climate policy you think the world will follow.

Choose your model parameters

Move these two sliders to change how your model simulates the climate.

Run your model

Now, click “Run Model” to see your results!

Model results

Your simple model projects that by 2100, the Earth's average surface temperature will increase

Now, let's compare your result with results from state of the art models.

Comparison with other models

Your simple model's projection for average temperatures between 2081 and 2100 is

We should also see how well your model fits past observations.

Comparison with past observations

These graphs show four different measurements of past climate. If the red line is almost always in the blue range on each graph, your simple model matches past observations well, so it's also likely to project future temperatures well. If it doesn't, your choice of parameters might have led to an inaccurate model!

Explore!

You now have access to all the features of this application. Try varying your policy selections to understand the implications of each decision!

The options listed here correspond to the Representative Concentration Pathways, or RCPs, created by the Intergovernmental Panel on Climate Change. Rather than representing specific policies, these pathways describe possibilities for atmospheric greenhouse gas concentrations, which are affected by both policy and natural variation. We have summarized them in terms of policy for convenience.

The RCPs are a worldwide standard for concentration scenarios, and therefore enable comparisons between many different models.

For more information, see this guide.

To simulate the behavior of the climate, models use equations derived from observations and experiments. Some of these equations include numbers, called “parameters,” which scientists can't measure exactly. Instead, they estimate the likelihood of each possible value, producing the green curve shown on the graphs below.

If you change the sliders below, your model's results will change. However, not all of the results you can produce are reasonable, as you can see by comparing your model's results to past observations and the results of other models. In particular, using two “very unlikely” values can produce wildly improbable projections.

The green bar shows the 5th to 95th percentile range of Coupled Model Intercomparison Project phase 5 (CMIP5) runs for the selected scenario. CMIP5 includes 42 models from research groups around the world, all of which are atmosphere-ocean general circulation models, the most sophisticated type available. Its results were used for the Intergovernmental Panel on Climate Change's most recent report.