The IPCC’s untapped resource: the frequently asked questions

  • 03 Nov 2014, 09:41
  • Robert McSweeney

This Sunday, the Intergovernmental Panel on Climate Change (IPCC) will publish its latest Synthesis Report, a non-technical summary of three huge Assessments Reports.

But there is another easily-accessible IPCC resource that has already been published and is often overlooked: the IPCC's Frequently Asked Questions.

So what information does an FAQ written by the world's top climate scientists provide?

Here are some of the questions they cover:

- FAQ 1.1: If understanding of the climate system has increased, why hasn't the range of temperature projections been reduced?

- FAQ 2.1: How do we know the world has warmed?

- FAQ 2.2: Have there been any changes in climate extremes?

- FAQ 3.1: Is the ocean warming?

- FAQ 3.2: Is there evidence for changes in the Earth's water cycle? 

- FAQ 3.3: How does anthropogenic ocean acidification relate to climate change?

- FAQ 4.1: How is sea-ice changing in the Arctic and Antarctic? 

- FAQ 4.2: Are glaciers in mountain regions disappearing?

- FAQ 5.1: Is the Sun a major driver of recent changes in climate? 

- FAQ 5.2: How unusual is the current sea level rate of change?

- FAQ 6.1: Could rapid release of methane and carbon dioxide from thawing permafrost or ocean warming substantially increase warming? 

- FAQ 6.2: What happens to carbon dioxide after it is emitted into the atmosphere? 

- FAQ 7.1: How do clouds affect climate and climate change?

- FAQ 7.2: How do aerosols affect climate and climate change?

- FAQ 7.3: Could geoengineering counteract climate change and what side effects might occur?

- FAQ 8.1: How important Is water vapour to climate change?

- FAQ 8.2: Do improvements in air quality have an effect on climate change?

- FAQ 9.1: Are climate models getting better, and how would we know? 

- FAQ 10.1: Climate is always changing. How do we determine the causes of observed changes?

- FAQ 10.2: When will human influences on climate become obvious on local scales?- FAQ 11.1: If you cannot predict the weather next month, how can you predict climate for the coming decade?

- FAQ 11.2: How do volcanic eruptions affect climate and our ability to predict climate?

- FAQ 12.1: Why are so many models and scenarios used to project climate change?

- FAQ 12.2: How will the Earth's water cycle change? 

- FAQ 12.3: What would happen to future climate if we stopped emissions today? 

- FAQ 13.1: Why does local sea level change differ from the global average? 

- FAQ 13.2: Will the Greenland and Antarctic ice sheets contribute to sea level change over the rest of the century?

- FAQ 14.1: How is climate change affecting monsoons?

- FAQ 14.2: How are future projections in regional climate related to projections of global means?

more

Probing the deep: An in-depth look at the oceans, climate change and the hiatus

  • 20 Oct 2014, 08:40
  • Roz Pidcock and Rosamund Pearce

Oceans cover more of the planet than anything else. So it makes sense that we need to know what's happening to them to understand how humans are changing the climate. 

If you follow climate science, you'd be forgiven for being a little confused recently by different news reports suggesting the oceans are warming, slightly  cooling or doing  nothing at all.

So are the oceans hotting up or aren't they? And how does what happens beneath the waves influence what we feel up here on earth's surface? Here's our top to bottom look at the oceans and climate change.

More heat in, less heat out

Scientists have known for centuries that greenhouse gases in the atmosphere, such as carbon dioxide and methane, trap heat and warm the planet. This is known as the greenhouse effect.

Scientists use satellite measurements to monitor how much of the sun's energy enters earth's atmosphere. A different set of measurements tells them how much finds its way out again.

The difference between those numbers is increasing, which means the earth is  trapping more heat than it used to. And that means the planet  must be warming.

A hiatus in surface warming

An interesting question is why temperatures at earth's surface - that's the air above land and the very top of the ocean - don't always reflect what's happening to the planet as a whole.

Over the last 15 years or so, surface temperatures have risen  much slower than in previous decades, even though we're emitting greenhouse gases  faster than we were before.

This is what's become known as the "hiatus", "slowdown" or even "pause" in surface warming.

This raises an obvious question. If earth is  gaining heat but the surface isn't warming very much, where is the heat going instead?

Where does the heat go?

Oceanheatadjustedocean 2nologo

more

How we can make good decisions about geoengineering

  • 30 Sep 2014, 15:15
  • Dr Rob Bellamy

Next month's synthesis report from the Intergovernmental Panel on Climate Change (IPCC) is due to give the organisation's verdict on geoengineering, a radical set of proposals to use large-scale technologies to tackle climate change.

There are two types of geoengineering. Carbon geoengineering seeks to remove carbon dioxide from the atmosphere, for example by capturing it from the air and storing it underground, or by adding iron to the oceans to trigger carbon-absorbing algal blooms.

Solar geoengineering is different. It seeks to reflect some sunlight away from the Earth before it can be trapped by greenhouse gases.This can be done, for example, by spraying clouds with sea salt to make them more reflective, or by stratospheric aerosol injection, where reflective particles are pumped into the atmosphere.

Geoengineering

My colleagues and I have been  examining the importance of 'opening up' discussion about geoengineering to alternative options, different perspectives and real world complexity.

'Closing down' assessment

Our earlier research has shown that the ways in which researchers frame assessments of geoengineering have important effects on the conclusions people come to.

more