Analysis

Hotter and wetter extremes: How scientists know our weather’s getting more erratic as climate change bites

  • 12 May 2014, 11:00
  • Roz Pidcock

From rising flood risk in the UK to record-breaking heatwaves across Australia, elevated greenhouse gases mean we're seeing warmer and wetter extremes in our weather than a century ago, says Dr Markus Donat.

Markus Donat researches extreme weather at the Centre of Excellence for Climate System Science and the Climate Change Research Centre at the University of New South Wales, Australia.

1. What type of weather events do you look at, and how do you define "extreme"?

My work focuses on temperature and precipitation extremes. In both cases, "extreme" means particularly high and particularly low values, compared to the expected range in a given region.

That means we look at peak temperatures and heat waves, as well as cold spells. For precipitation, "extreme" can mean unusually heavy rainfall over a single day or over several consecutive days. Unusually long periods without any rain are also a type of extreme event.

2. How do scientists measure extreme heat and rainfall events? How good is the data?

We've been working on creating a global database of observations, which means overcoming several big challenges. One issue is data gaps. We have very good observational coverage in the northern hemisphere and in Australia, for example, but large gaps in Africa and South America. Sometimes data exists in written archives, but has never been digitised.

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Analysis: Newspaper coverage of climate change drops despite release of major UN reports

  • 06 May 2014, 14:00
  • Mat Hope

Credit: Roland Unger

Despite the launch of  two major UN reports on climate science, UK newspaper coverage of climate change dropped last month.

The UN's Intergovernmental Panel on Climate Change (IPCC) has released threemajor reports on the causes and impacts of climate change over the past seven months. The publication of the first report last September led to a spike in newspaper coverage. But the latter two reports - launched on the 31st March and 13th April - didn't capture the same level of attention, our analysis suggests.

climate tracker, total, April 2014

Our analysis shows 452 articles were published in April, just two more than an 12-month average of 448 articles per month. That's significantly less than February's 12-month high, where floods catalysed a widespread debate on the impacts of climate change.

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Q & A: What’s El Niño - and why does it matter that scientists say one is on the way?

  • 24 Apr 2014, 12:50
  • Roz Pidcock

Forecasters worldwide are issuing alerts. Later this year, we're likely to be in the midst of an El Niño - a phenomenon driving severe weather worldwide. So when can we expect it to kick in, and what will the consequences be for global temperature? Find this and more in our quick Q & A.

What is an El Niño?

Every five years or so, a change in the winds causes a shift to warmer than normal ocean temperatures in the  equatorial Pacific Ocean - known as El Niño, or cooler than normal - known as La Niña, moving briefly back to normal in between.

Both phases together are known as the El Niño Southern Oscillation (ENSO), and are responsible for most of the fluctuations in global weather we see from one year to the next.

ENSO

Sea surface temperature during El Niño (left) and La Niña (right). Red and blue show warmer and cooler temperatures than the long term average. [Credit: Steve Albers, NOAA]

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Media reaction: The Intergovernmental Panel on Climate Change's big climate mitigation report

  • 14 Apr 2014, 12:50
  • Mat Hope

While many were still engulfed in their duvets recovering from the night before, the UN spent Sunday morning launching a big report on strategies to tackle climate change. The report was the third instalment of the Intergovernmental Panel on Climate Change's (IPCC) major review of the most up-to-date climate change research.

If you've been too busy to catch up on the swathes of media coverage since then, have no fear - we've speed-read it all for you:

International cooperation

A significant proportion of the media focused on the report's message that there is still time for countries to act to avoid the worst impacts of climate change - but only if they work together.

  • The  Financial Times said the IPCC was sure there is "still time to save the world". It quotes one of the report's co-chairs, Ottmar Edenhofer, saying the report carried "a message of hope"  that tackling climate change "can be done".
  • Doing so would mean cutting emissions "by up to 70% by 2050 if it is to prevent global temperatures rising by more than two degrees", the  Sunday Times reports. The IPCC's research shows "stabilising climate is humanity's biggest challenge", it adds.
  • Newswire  Agence France Presse described the report's findings as a "wake up call" for governments. It said the IPCC identifies a 15-year window in which countries' will be able to act to avoid the worst impacts of climate change.
  • That means "governments must do more" to address rising emissions, the Washington Post argues. Countries must work together to lower emissions by 40 to 70 percent, according to the IPCC's findings, it said.
  • Taking a slightly different angle, the  Independent on Sunday was the only major UK newspaper to focus on the consequences of inaction. Unless the world acts soon, the IPCC says emissions could reach a level "that could reap devastating effects on the planet", the newspaper reports.

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The what, when and where of global greenhouse gas emissions: A visual summary of the IPCC’s climate mitigation report

  • 13 Apr 2014, 10:50
  • Mat Hope

Erhard Renz

The UN Intergovernmental Panel on Climate Change (IPCC) released the third and final instalment of its big report today. It calls for policymakers across the globe to come together to formulate ways to cut greenhouse gas emissions and avert the worst impacts of climate change.

The IPCC provides a number of charts and graphics to illustrate the complex report - some more obvious than others. We do our best to translate three of the most startling, showing what the IPCC says must be done, when emissions need to be cut, and where those reductions can be made.

What must be done

In 1992, countries agreed to curb global greenhouse gas emissions to try and prevent temperatures from rising by more than two degrees above pre-industrial levels. For this to remain possible, countries are going to have to make some significant emissions cuts over the coming decades, the IPCC says.

This graph shows how emissions will have to change between now and 2100 if the world is going to avoid the worst impacts of climate change, according to the IPCC's modelling:

WG3 SPM Emissions Pathways

Each of the coloured strips is a different emissions pathway - or scenario - that the IPCC has modelled.

The amount of warming the world will experience is related to the proportion of greenhouse gases in the atmosphere, known as the emissions concentration. There's about a 66 per cent chance of keeping warming to two degrees if the emissions concentration stays between 430 and 480 parts per million (ppm) of carbon dioxide equivalent by 2100, the IPCC estimates - the light blue strip on the graph above.

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‘Misleading the reader’: The Intergovernmental Panel on Climate Change responds to Mail on Sunday claims

  • 07 Apr 2014, 17:30
  • Mat Hope

In an article in this weekend's paper, the Mail on Sunday  accuses the Intergovernmental Panel on Climate Change (IPCC) of 'sexing up' its findings in the short 'summary for policymakers' that accompanies its latest report. But the IPCC  responded this morning, saying the Mail on Sunday "misleads the reader by distorting the carefully balanced language of the document".

In an effort to help policymakers and the public engage with its mammoth scientific reports, the IPCC produces a summary - the  Summary for Policymakers (SPM). It tries to present the report's overall conclusions in a shorter and more accessible format.

The Mail on Sunday has done a comparison between the SPM, and quotes it claims come from the full IPCC report. The article says the SPM puts an "alarmist spin" on the findings, but the IPCC has today  rejected that charge in a statement.

We look at what the report has to say, and the Mail on Sunday's troubling presentation of the evidence.

Wrong chapter, misleading attribution

The Mail on Sunday says the IPCC's SPM over-emphasises the extent to which climate change is expected affect a range of other issues, starting with how it could force migration as extreme weather hits people's local environments.

But the IPCC defends the SPM's finding, saying the Mail on Sunday has cherrypicked quotes that don't reflect the report's overall conclusions.

Here is the Mail on Sunday's accusation:

MoS migration

The IPCC says the Mail on Sunday ignores important evidence on migration in the report that supports the SPM statement.

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The IPCC's risky talk on climate change

  • 04 Apr 2014, 12:00
  • James Painter

There can be no doubt how Professor Chris Field wanted the latest Intergovernmental Panel on Climate Change (IPCC) report to be understood.  As well as being co-chair of the IPCC's Working Group 2, Professor Field is an astute media performer with a keen sense of clear messages. 

So it was highly significant just how much emphasis he put on the idea of framing the climate change challenge as one of risk management.

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Analysis: How UK newspapers covered the IPCC’s report on the impacts of climate change

  • 03 Apr 2014, 16:15
  • Mat Hope

Emett Bergin

From food shortages to endangered species, there were plenty of headline-grabbing findings in the UN's latest big climate report. We take a look at how the UK's newspapers covered the Intergovernmental Panel on Climate Change's (IPCC) latest report.

The IPCC's Working Group 2 (WG2) report on the impacts of climate change was released on March 31st. Monday's report was the second in a series of three from the IPCC. The first report - Working Group 1's on climate change's physical science basis - was a  big story when it was released last September, so it's perhaps unsurprising that WG2's report also received quite a lot of attention.

But despite being overseen by the same organisation, the two reports are very different beasts. While journalists generally focused the WG1 report's topline finding that scientists were more certain than ever about humans influence on the climate, WG2's broad focus led newspapers to print stories on a wide variety of issues: from flooding in the UK, to famine in parts of Africa.

Coverage

We searched the UK's main national newspapers for coverage of the report in the two weeks leading up to its release (a more detailed methodological note can be found at the end of the blog). There were 49 articles in the mainstream press over the 15 days our search covered.

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Risk, resilience and honeybees: Scientists' views on the new IPCC report

  • 02 Apr 2014, 14:55
  • Roz Pidcock

Hundreds of scientists from more than 70 countries helped pull together the new report from the Intergovernmental Panel on Climate Change (IPCC). Now it's published, here's what a few of them have to say about the report's messages, and what should happen now.

"No question" the risks are real ...

The IPCC report defines what the research community knows and doesn't know about climate change. Chris Field, co-chair of the group that produced the report, told journalists on Sunday:

"Our job is to represent the full range of scientific and technical views on this critically important issues. When the IPCC does a report, what you get is the community's position."

And the report is unequivocal on the fact that human interference with the climate system is already occurring. Field adds:

"We see impacts from the equator to the poles and from the coast to the mountains. There's no question we already live in a world that altered by climate change"

We're already seeing more frequent extreme weather, food and water shortages, shrinking glaciers and species migrations, the report says. And as climate economist, professor Nicholas Stern, points out:

"These are all happening after less than one degree centigrade of global warming."

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BBC climate coverage singled out for criticism by cross-party parliamentary committee

  • 02 Apr 2014, 00:00
  • Ros Donald

The government, the media - particularly the BBC-  must up their game in communicating the science of climate change to the public. That's the conclusion of a report by a Parliamentary select committee, out today. 

Detrimental to trust

"A lack of clear, consistent messages on the science has a detrimental impact on the public's trust in climate science."

So says the cross-party Science and Technology Committee's report, 'Communicating climate science', compiled following evidence sessions with a range of experts and representatives of government and the media.  It calls on the government to implement a strategy for communicating climate change "as a matter of urgency" and has harsh words for media outlets that it says have been guilty of confusing scientific evidence with opinion. 

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