How scientific researchers calculate climate change?
The biggest topic of our time is climate change and we are at a critical moment. The consequences of climate change are worldwide and unparalleled in scope, ranging from shifting weather patterns affecting food production to increasing sea levels that raise the likelihood of catastrophic floods. Adapting to these potential impacts will be tougher and more expensive without drastic action today.
Greenhouse Gases & Humans
Greenhouse gases are natural and essential if human beings and millions of other living things are to survive by preventing some of the warmth of the sun from returning to space and making this earth livable.
But over a century and a half of industrialisation, deforestation and large-scale farming have seen an increase to record volumes of greenhouse gas in the atmosphere over three million years. The combined level of greenhouse gas ( GHG ) emissions is also rising with the population, economies and standard of living.
The basic scientific links are well established:
- The Earth’s concentration of GHGs is directly related to the average global Earth temperature;
- Since the Industrial Revolution, concentration has been steadily increasing and mean global temperatures;
- Carbon dioxide ( CO2) is the most abundant GHG, representing approximately two-thirds of the GHGs.
Human dependency on fossil fuels heats the planet at a rate that is unprecedented. The actions that science has told about the impact of climate change on the Earth must guide governments and policymakers.
Vilhelm Bjerknes, formulas that combined the flow of heat, water and air were developed at the end of the 19th century. His idea further helped to find a first computer atmospheric model 50 years later, which gave birth to contemporary weather forecasts. The current climate models are the most advanced descendants of the original, except that computers are around 25 times faster.
How does weather forecast work?
The atmosphere of the planet is divided into a grid of hundreds of thousands of atoms, stacks like a skyscraper. The Met Office, the national weather service in Britain for example, uses 85-cell stacks. Then the models calculate how energy, air and water vapour flow over a certain time period through each cell. During weather forecasts, the environment takes a snapshot and predicts what will occur over the next days.
For years and years, climate models consider the behaviour of the atmosphere that simulates both the world as it is and the world as it may be. It describes the kind of procedures and the kind of outcomes you can expect, and this helps you somewhat to notify policy. One of the classic things that climate models have ever done is simply to look around the world when the carbon dioxide level was twice the current level. How scientific researchers calculate climate change?
This was one of the first ways climate models began to show that greenhouse warming was a problem in the 21st century. These models have constraints for all their complexity. While you cut the atmosphere into millions of cells, the atmosphere is still quite big, and a millionth of a big thing. So cells tend to be hundreds of miles alongside them.
This means that the models also fail to capture details such as the weather and clouds play a major role in the environment. As greenhouse gases make the atmosphere warmer they change how much water vapour they can retain and how the air goes up and down. Depending on where the clouds form, they can either traps sunlight which warms the earth or reflect it back in space, which refreshes it. And a number of processes governing cloud formation work very little so that those precise processes can not be modelled in computer models.
You have to create different thumb rules in order to know what the clouds think you ‘re doing. How you do that means your model would be different from the model of anyone else. There are hundreds of these models run by worldwide teams. Modellers all want to understand the Earth as closely as possible, but their assumptions as to what works actually vary from model to model and how these assumptions are being implemented.
There are models that tend to, people say, be hot, so they tend to warm up a certain quantity and some models tend to be cold every few years when standardized questions are raised and their results are compared. This allows scientists to consider and develop the strengths and limitations of different climate models.
Of course, the potential predictions of the models can not be measured but what researchers can do is to compare the performance of the models from past decades. The latest study compared the 1970s to the 2000s models and found that, overall, they were fairly strong, because the warming we had already observed was part of the error bars for most so it gave you a similar general sense.
The climate models are becoming more and more complicated in capturing more of the planet’s aspects. But there is one element, that can’t be modelled And it is the major contributor to climate changes. The issue of human activity is that you can not get it inside the model. The model deals with the sort of like physical laws of chemistry and physics and biology. So, there’s no way the model can say, well, in 2050 America will have stopped emitting carbon dioxide. Instead, scientists take simplified results from these climate models and run them through economic models.
In 2013, researchers utilized these models to study the impact on the future temperature of the planet of different climate policies that included:
- What would happen if there was continued large-scale use of coal?
- If there would be continuous use of fossil fuels but some use of renewable energy.
- If there was a much higher uptake of renewable energy.
- If there was a lot of use of carbon-capture technology and more land to grow biofuels.
The remarkable feature of these comparisons is that only really tough climate policies can give you the kind of route that keeps the temperature far below 2 degrees above pre-industrial in the words of the Paris Agreement. What these models tell us is that the current emission reduction level is not remotely sufficient to ensure you are still less than two degrees or close to 1.5.
Climate models are not forecasting the future and are not perfect. We have a long way to go until they completely represent all the dynamic processes of the World. But they are currently the only way for scientists to understand how harmful an increase in carbon dioxide is to the planet. The solution to climate change will ultimately not lie within models, but rather what people choose to do with the information they provide.
How scientific researchers calculate climate change?