Scientists warn of looming climate ‘disaster’

Getting warm: In 2016 NASA said some Antarctic ice could be in “irreversible decline”. © Getty

Scientists have greeted President Trump’s decision to withdraw from the Paris climate agreement with dismay. What could the implications be? And could scientists solve climate change?

Three billion tonnes per year.

That is how much extra carbon dioxide the USA could now pump into the atmosphere by 2030. Yesterday scientists estimated that President Trump’s decision to remove his country from the Paris climate deal would increase global warming by 0.3°C by the end of the century.

And some said countries such as India may follow the US lead. “There will be ripple effects around the world,” said climate scientist Katharine Hayhoe.

So what impact could this have?

1/ Rising seas. As carbon dioxide accumulates, ice will melt and seawater will expand. NASA expects global sea levels to rise by between one and four feet by 2100. This will submerge low-lying islands and even many cities.

2/ Flooding. As the atmosphere warms, more rain will fall. Global warming changes circulation patterns in the atmosphere, intensifying natural weather systems and leading to more extreme events such as hurricanes.

3/ Drought. Changing weather systems can bring long dry spells. And rising temperatures will make soil drier. In 2015 some scientists said man-made global warming had made a drought in California between 15% and 20% worse.

4/ Extinction. Animals and plants are very sensitive to temperature. In 2015 a major analysis suggested warming temperatures could kill one in six species worldwide in the next century.

5/ Famine. Climate change will disrupt the food chain and drought will make it harder to grow food or access water. In March the UN said 1.4m children could soon die from malnutrition, as a result of famine caused partly by climate change.

6/ Migration. If areas become uninhabitable, especially in the developing world, people will move elsewhere in large numbers. This will increase competition for resources and could exacerbate social tensions and wars.

7/ Disease. The changing climate will alter how and where people live. This could expose them to more disease-carrying animals. And as areas get warmer, the habitats for insects such as mosquitoes expand — so illnesses are likely to spread.

Hostile climate

This problem is too vast, say some. The Earth’s temperature is changing much faster than it naturally should. We cannot undo industrialisation, which has given us longer and more prosperous lives. And scientists, who are trying to mitigate so many of the problems caused by climate change, are overwhelmed.

“Such pessimism!” respond others. Scientists are already hard at work finding solutions. We now have several practical sources of clean energy. New techniques are making farming greener. And genetically modified crops could be resistant to drought. Scientists invented antibiotics and put men on the moon; they can solve this.

You Decide

  1. Does climate change worry you?
  2. Will scientists solve climate change?

Activities

  1. Work in pairs. Write a list of five questions you would like to ask an expert on climate science. Explain to your class why you think your questions are interesting.
  2. Choose one of the seven effects of climate change listed in this article. Write a one-page memo explaining how it is linked to climate change and what impact it could have in the next century.

Some People Say...

“There is no problem on Earth that science cannot solve.”

What do you think?

Q & A

What do we know?
According to NASA, global sea levels have risen by about 8 inches since reliable record keeping began in 1880. In recent years it has accelerated as extra carbon dioxide has accumulated in the atmosphere. And the type of carbon which is increasingly present is carbon-12, which is emitted when fossil fuels are burnt. The poles are warming faster than the rest of the planet, so ice is melting quickly.
What do we not know?
How much impact the US decision will have. One team ran a computer simulation and said its impact would be between 0.1°C and 0.2°C. Some experts think the USA’s carbon emissions will continue to fall, although not as quickly as they would otherwise. This is largely because renewable energy sources are becoming more readily and cheaply available.

Word Watch

0.3°C
According to models by Climate Interactive, a not-for-profit organisation based in Washington, DC.
Rain
According to Adam Scaife, the head of long-range prediction at the UK’s Met Office, a 1°C increase in temperature increases the water vapour in saturated air by 7%.
Systems
Such as El Niño, a system created when warm water in the Pacific Ocean moves east near the Equator.
Worse
A. Park Williams, a climate scientist at Columbia University, said: “It would be a fairly bad drought no matter what. But it’s definitely made worse by global warming.”
Sensitive
Some animals can move, for example to be nearer the poles or on higher ground. But their ability to do so is limited — for example, because they are tied to a source of food. Changing temperatures also alter food chains, leaving animals without enough to eat.
Analysis
According to a study published in the journal Science.
Numbers
This problem will be made more acute by the rising global population.
Mosquitoes
Humans have already contracted diseases such as Zika and malaria, which are borne by mosquitoes, in unexpected areas.

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