Could we control our climate?
Could we control our climate?

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Could we control our climate?

1 The climate forecast

How can scientists predict climate change in a hundred years, when they can’t even predict the weather next week? The answer will hopefully become clear in Activity 1.

Activity 1 Heads or tails?

Timing: Allow approximately 10 minutes

Find a coin and a volunteer.

Ask your volunteer to toss the coin six times in a row. But before they start, ask them to write down a prediction for what the results will be: for example, ‘heads, tails, heads, tails, tails, heads’.

Were they right?

Answer

Chances are they were not! In fact, your volunteer had only a 1.6% chance of getting it right (0.5 multiplied by itself six times).

Now do the same again but ask your volunteer to make a different prediction: to write down how many heads there will be out of the six coin tosses.

Do they get this prediction right? If so, can you explain why this might be?

Answer

They are much more likely to get this right. This is because they are predicting the average frequency of heads over six coin tosses rather than making six separate predictions for each individual coin toss.

Does each type of prediction become easier or harder if you do the same activity with a larger number of coin tosses?

Answer

As the number of coin tosses increases, it becomes harder to predict the sequence of coins and easier to predict the fraction that are heads. The random fluctuations of a coin toss are ironed out the more times you try, so the average fraction of heads becomes closer to 50%.

Which of these is more like predicting weather, and which more like predicting climate, and why?

Answer

The first of these is like predicting weather because the sequence of specific coin tosses is analogous to a sequence of day-by-day events. The second is like predicting climate because the frequency of heads is analogous to the frequency of different types of weather.

However, predicting climate is – in one important sense – harder than predicting the statistics of coin tosses. In the coin toss activity, everything about the environment stays the same each time. This is why it becomes easier to predict the average number of heads as the sequence of coins becomes longer. In the real world, both human-caused and natural forcings will continue to change. This makes future climate harder to predict.

But the overall principle is similar – weather is a sequence of days and climate is a distribution of those days. This is an example of how the statistical definition of climate that you saw in Session 1 can contribute to confusion about how scientists predict it.

CC_1

Take your learning further371

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses372.

If you are new to university level study, we offer two introductory routes to our qualifications. Find out Where to take your learning next?373 You could either choose to start with an Access courses374or an open box module, which allows you to count your previous learning towards an Open University qualification.

Not ready for University study then browse over 1000 free courses on OpenLearn375 and sign up to our newsletter376 to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371