The phrase “climate change” has been mentioned more than 19,000 times in British parliamentary debates, with Labour politicians using the term more than representatives from any other party.
These are among the findings to emerge after Carbon Brief extracted data from more than 200 years of records from the UK’s houses of Commons and Lords.
The analysis reveals how the climate conversation in British politics has shifted over the years, from discussing the “greenhouse effect” in the late 1980s to more recent debate over the “climate crisis”.
It also shows which MPs and peers have devoted the most time to this issue, whether that means arguing for more action to tackle global warming, or less.
Read on for a breakdown of how this discussion is split both along party lines and among individual politicians, as well as a dive into the history of political language around climate change. Key insights include:
- Labour MPs and peers have used the term “climate change” some 8,463 times compared to 5,860 mentions from Conservatives and – compared to their relatively lower numbers in parliament – a disproportionate 2,426 for the Liberal Democrats.
- Current Conservative prime minister Boris Johnson has mentioned “climate change” just 10 times, against 40 for opposition leader Jeremy Corbyn, 65 for Liberal Democrat leader Jo Swinson and 143 for former Green leader Caroline Lucas.
- The terms “greenhouse effect” and “global warming” were commonly used from the 1980s but have been largely replaced, since the late 1990s, by “climate change”. More recently, terms such as “climate crisis” have entered use in parliament.
- Some 576 MPs – the vast majority of the UK’s 650 total – use Twitter. But only 64 of them (12%) follow climate scientists on the platform, of which 42 are Labour MPs.
Which politicians talk most about climate change?
To find out which MPs and peers have been most vocal about climate change over the years, Carbon Brief analysed data from Hansard, the official report of all parliamentary debates.
As the Hansard record stretches back over two centuries, it documents the first times terms such as “greenhouse effect” and “climate change” were mentioned in parliament, as well as the periods in which these issues came to the forefront of British politics.
While the analysis is comprehensive, a relatively small fraction of the climate mentions could not be matched to politicians, or did not have names attached to them. There is however no reason to expect these omissions to be biased towards particular parties or individuals. There is also a gap in the Hansard data from around April 2005 through June 2006. See below for more details on the methodology behind the analysis.
In recent decades, certain politicians have emerged as champions of climate action, leading the development of everything from the Climate Change Act in 2008 to the more recent net-zero target. Others have been more reticent or outright hostile towards such action.The proportion of mentions of different climate terminology in parliamentary debates that can be attributed to each of the major political parties. This chart does not include the mentions for which there was no name attached to the search result, which range between 1-7% for the phrases “climate change”, “global warming” and “greenhouse effect”. It also does not include the mentions for which the name could not be linked to a political party, which ranged between 1-11% for those three phrases. “Other” includes minor political parties, as well as crossbench peers, bishops and independent representatives. Source: Carbon Brief analysis of Hansard. Chart by Carbon Brief using Highcharts.
Overall, the records suggest that Labour have been the most vocal party on this topic, with its MPs and peers mentioning “climate change” 8,463 times and “global warming” 947 times. This compares to 5,860 and 769 times respectively for the Conservatives.
This trend is reversed for the term “greenhouse effect”, which largely fell out of use in British politics during the early 1990s. Conservatives have mentioned the term 225 times compared to Labour’s 183, with most of the early discussions taking place in the House of Lords.
It is worth noting that despite being a far smaller party, the Liberal Democrats appear to have made a disproportionate contribution to the climate conversation. Their representatives have mentioned “climate change” 2,426 times and “global warming” 292 times. As Carbon Brief was going to press, for example, the Liberal Democrats had just 17 MPs in parliament compared to Labour’s 248.
Labour, along with smaller parties including the Liberal Democrats, Greens and the Scottish National Party have also made greater use of the dramatic new language that over the past year has come to characterise climate discussions.
Members of these parties have collectively racked up 339 references to a climate “crisis”, “emergency” or “catastrophe”, whereas the ruling Conservatives have only used these terms 32 times. The Green MP Caroline Lucas is single handedly responsible for 31 mentions.
Among current party leaders, Jo Swinson of the Liberal Democrats has accrued the most mentions of “climate change”. In her 12 years as an MP, she has used the phrase 65 times in parliament, compared to Labour leader Jeremy Corbyn, who has mentioned it 40 times in his 36 years as MP for Islington North. (Corbyn has, however, been a frequent user of newer terminology in recent months, mentioning “climate emergency” more than any other MP.)
Conservative prime minister Boris Johnson, meanwhile, has used the term “climate change” just 10 times during his time in parliament.
David Cameron, before her, reached 95 during his parliamentary career, which saw him visit the Arctic to highlight climate change and promise the “greenest government ever”, but also reportedly pledge to cut the “green crap” in a bid to reduce energy bills.
The prime minister who has used the term most during their time in politics is Gordon Brown, who oversaw the implementation of the Climate Change Act and mentioned climate change 101 times.
None of these leaders enter the top ten for mentioning climate change, however, as shown in the chart, below. Instead, frontrunners in the climate conversation have generally emerged due to roles as prominent figures in climate or environmental policy.
Lord Rooker, a former Labour environment minister who introduced the Climate Change Act in the House of Lords in 2007, is at the top of the ranking with 229 mentions. He is followed by the Liberal Democrat peer and vocal climate advocate Lord Teverson, on 210.Number of mentions of “climate change” by the ten MPs and peers to have used the phrase the most. Colours of bars indicates their political affiliation (red=Labour, blue=Conservatives, orange=Liberal Democrats. Source: Carbon Brief analysis of Hansard. Chart by Carbon Brief using Highcharts.
The first sitting MP on the list is Sir Ed Davey, who served as energy and climate change secretary from 2012 to 2015 in the Conservative-Liberal Democrat coalition government. He has referred to climate change 184 times.
Other notable names at the top of the rankings include former Labour leader and the first secretary of state for energy and climate change Ed Miliband, and Lord Deben, former Conservative environment secretary and current chair of the Committee on Climate Change. They have mentioned climate change 182 and 160 times, respectively.
Focusing on the far less common term “global warming” once again reveals a list largely dominated by prominent climate advocates including Lord Deben and former Conservative climate minister Lord Barker of Battle.
However, the most frequent user of the term in parliament is Lord Peter Lilley, Conservative trustee of the climate sceptic Global Warming Policy Foundation and one of only three MPs to vote against the Climate Change Act, who once claimed his reason for doing so was that it was snowing in October.
How has the language of climate change shifted over the years?
The language used to describe the changes to the planet associated with greenhouse gas emissions has shifted as the years have passed. This has been reflected in discussions among scientists, the media, the general public – and also parliamentarians.
While “global warming” and “climate change” were entering common parlance towards the end of the twentieth century, the first ever mention of this topic in British politics came a little earlier, and from an unusual source.
The records reveal that during a 1969 discussion about railway policy – specifically “with regard to laying down long welded rail” – Jestyn Philipps, the Viscount St Davids, asked the following question:
“My Lords, can my noble friend say whether he and British Railways have taken account of the fact that what were abnormal temperatures last summer may not be abnormal if we continue to discharge CO2 into the air by the burning of various fossil carbons, so increasing the greenhouse effect?”
In the scientific community, the idea that certain gases could trap heat from the sun and affect the temperature of the planet was not new by the 1960s. It was a concept that had first been advanced in the 19th century, gradually gaining traction in the decades that followed.
Nevertheless, the viscount’s reference is fairly incongruous. After this early mention, the greenhouse effect is effectively overlooked by politicians until the late 1980s.
As evidence mounted for rising levels of atmospheric CO2 and an accompanying rise in global temperatures, the Intergovernmental Panel on Climate Change (IPCC) was established by the UN in 1988.
Within just two years, parliament held six debates featuring the phrase “greenhouse effect” in the title, and there was a large spike in its use among MPs.
Around this time, the term was joined and ultimately superseded by the broader phrases “global warming” and then “climate change”.Number of uses of the phrases “greenhouse effect”, “global warming” and “climate change” between 1955 and the end of August 2019. Source: Carbon Brief analysis of Hansard. Chart by Carbon Brief using Highcharts.
While the picture was not yet complete, some of the early references to global warming show that the key facts about climate change were understood early on by some politicians.
In a lengthy speech introducing the concept in 1978, Conservative peer Lord Tanlaw told his fellow peers about the “whole problem of atmospheric CO2 and…a sudden and unpredictable change in the world’s weather patterns.”:
“This problem is an entirely novel one in that it may create an entirely new set of conditions to be met by government agencies at national and international level.”
However, he concludes that in his view “the net effects may be both beneficial and agreeable rather than catastrophic – provided the ‘greenhouse effect’, to which I have referred, does not turn into a runaway situation”:
“[T]he recent weather changes appear, so far, to augur well for mankind. On that note I should like to conclude, and it is an optimistic note at that.”
In the ensuing debate, peers discuss the possibility of ice caps melting, crops being affected by disrupted weather patterns, and low-lying nations such as the Netherlands bearing the brunt of rising sea levels.
While one peer says it at first sounds like a topic that “deserved more attention from Dr Who” than the House of Lords and another offers a “pet theory” that radioactivity is to blame for unusual weather, they broadly appear to accept and express concern about the growing scientific consensus.
In a 1984 environmental pollution debate in the House of Commons, Conservative MP Nigel Forman made a comment that foreshadows much of the subsequent debate:
“Since the greatest contribution to the ‘greenhouse effect’ comes from the burning of fossil fuels, does that not have important implications for our energy policies and those of other countries, since we are not the largest burners of fossil fuels?”
A concerted focus on global warming begins in earnest towards the end of the 1980s. Conservative prime minister Margaret Thatcher, who made key speeches on the topic to the Royal Society and the UN around this time, tells parliament she “recognise[s] the dangers that could arise from the greenhouse effect”.
By the end of the 20th century, “climate change” was becoming the preferred term in British politics, with its use spiking at key times such as the development of the Climate Change Act in 2007 and 2008, as well as around the Paris Agreement in 2015.
The first relevant mention of climate change comes in 1988 from Malcolm Sinclair, Earl of Caithness and Conservative environment minister, who assures his fellow peers that “the UK plays a leading role in international research” into this topic. In a debate later that year he proposes nuclear and renewables as government-endorsed strategies to cut emissions.
Climate change is generally considered a broader term that better encapsulates the range of effects resulting from rising planetary temperatures.
However, there is also evidence that its use has been encouraged to downplay the threat. For example, in the US a notorious 2002 memo from Republican strategist Frank Luntz to president George W Bush said the term was preferred because it was “less frightening” than global warming.
Recently, there has been a push from some quarters for a shift in the language used to describe climate change, and this has been reflected in British politics.
An early use of more emotive language to discuss climate change came from Labour MP Joan Ruddock in 2007, who told parliament:
“International cooperation on climate change, world trade and technology transfer are vital if we are not to face climate catastrophe and a scramble for diminishing resources.”
In recent months, with the emergence of Extinction Rebellion and Greta Thunberg, “climate catastrophe” is one of the terms that has entered the lexicon of campaigners and politicians who view it as a more effective way of conveying the current situation.
As of summer 2019, The Guardian has adopted “climate emergency, crisis or breakdown” as preferable terms to climate change and “global heating” is favoured over “global warming”.
As the charts below show, it is only in the past year that such terms have entered more common usage in parliament. A spike in their use by politicians – particularly Labour MPs – coincided with a speech from Thunberg in parliament, in which she emphasises the importance of acting soon to cut emissions.Number of uses of the phrases “climate catastrophe”, “climate crisis” and “climate emergency” between 2000 and the end of August 2019. Source: Carbon Brief analysis of Hansard. Chart by Carbon Brief using Highcharts.
The most frequent user of these more emotive phrases is Caroline Lucas, former Green leader and her party’s only MP. As a vocal supporter of climate action, Lucas is also one of the politicians who has mentioned “climate change” most in parliament, at 143 times. In May, she told parliament:
“The failure to act with sufficient ambition to avert the climate catastrophe will be the greatest moral failure of our time…The planet has been brought from seeming stability to the brink of catastrophe in my lifetime, so we have to turn things around in our lifetimes, too. It is the most awesome responsibility, but it is also the most amazing opportunity.”
Which MPs follow climate scientists on Twitter?
To get an idea of which politicians were the most enthusiastic about following developments in climate science, Carbon Brief also looked at data concerning who MPs had chosen to follow on Twitter.
The analysis was inspired by work undertaken earlier this year by Dr Robert Rohde, a lead scientist at Berkeley Earth, who compiled a similar ranking of the members of US Congress following climate scientists. To inform this piece, Rohde conducted the same analysis, but this time using information from the 576 UK MPs who use Twitter.
As Rohde has pointed out, politicians are capable of accessing far more resources than those available via Twitter. However, the results give an interesting insight into which ones are tuning into the latest climate science conversations in their feeds.
A total of 68 MPs follow at least one of the listed climate scientists on Twitter, 12% of all the members who use the platform. Of these MPs, 44 follow just one of the scientists and 42 are Labour members, as the chart below shows.Number of current MPs in each party that follow at least one climate scientist on Twitter, based on a list of “scientists who do climate” put together by atmospheric researcher Dr Katherine Hayhoe. Source: Analysis for Carbon Brief by Robert Rohde. Chart by Carbon Brief using Highcharts.
Among those at the top of the ranking are some of the MPs most known for their interest in climate and environmental issues. Labour’s former shadow minister for energy and climate change Jonathan Reynolds comes top, following 22 scientists from the list, with Green MP Caroline Lucas next on 17.
Labour’s former shadow environment secretary and advocate for veganism Kerry McCarthy follows 13 climate scientists from the list, while Labour’s Clive Lewis, who has been instrumental in launching a “green new deal” bill, comes closely behind on 12.
Besides Lucas and McCarthy, the top 10 list of MPs following climate scientists also includes two more members of the House of Commons Environmental Audit Committee, Labour’s Anna McMorrin and Mary Creagh.
When Rohde ran his US analysis, he was surprised to find that many of the country’s politicians who were vocal in their support of climate action were not engaging with climate scientists on Twitter. Neither Democrat presidential hopefuls Bernie Sanders and Elizabeth Warren, nor green new deal advocate and “Twitter superstar” Alexandria Ocasio-Cortez, followed anyone on the list.
There are some similar surprises in the UK analysis. Among the MPs following none of the listed climate scientists are former energy minister Claire Perry, and former environment secretary Michael Gove.
None of the leaders of the three major political parties follow any scientists on the list.
As for the scientists themselves, the most popular among the MPs were Prof Kevin Anderson from the University of Manchester and Prof Rebecca Willis from Lancaster University, with 10 and six politician followers respectively. Prof Richard Pancost from the University of Bristol and Prof Ed Hawkins from the University of Reading were close behind, with five each.The top 10 MPs following the most climate science communicators on Twitter. Source: Analysis for Carbon Brief by Robert Rohde. Chart by Carbon Brief using Highcharts.
The analysis of Hansard data was performed using Python and Google Sheets. It focused on the terms “climate change”, “global warming”, “greenhouse effect”, “climate crisis”, “climate emergency” and “climate catastrophe”.
Some parliamentarians appear under different names in the records. For example, Margaret Thatcher is recorded both under her own name and also sometimes as “The Prime Minister”, while John Gummer is referred to as Lord Deben once he takes up his position in the House of Lords. Records also refer at times to surnames only (“Mr Gummer”).
While it is possible to clean up the data to account for some of these issues, there remain a fraction of relevant references to the various climate terms that could not be matched, or did not have names attached to them in the data.
For example, when searching for “climate change”, there remain 746 mentions with no name attributed (4% of the total) and 258 names for which there is no match to a specific politician (1% of the total), usually in cases with common surnames.
In addition, there is an unexplained gap in the Hansard archive covering roughly April 2005 to June 2006. This gap is common to all search terms, not just those relating to climate.
There’s a strange gap in the results from the excellent Hansard archive search.https://t.co/AExvc4vbUb
It returns zero results from ~1/4/2005 to ~1/6/2006 (see image of search for “the”).
If anyone knows why please do get in touch! pic.twitter.com/374yU6TIeA
— Simon Evans (@DrSimEvans) September 10, 2019
As a result, the totals listed in the article for parties and individual MPs are likely to be missing a small fraction of their true numbers.
It is also worth noting that some of the mentions counted in the analysis are not, in fact, references to anthropogenic global warming. When the Marquess of Salisbury told his fellow peers they should “keep [their] eyes upon the possibility of such discussions, or any others, should the climate change”, during a debate about defence in 1955, we can be confident he did not have greenhouse gas emissions in mind.
Update 13/09/2019: A previous version of this article indicated the first mention of “greenhouse effect” came in 1959, as recorded in the online version of Hansard, the official record of parliamentary proceedings. However, another record of the same debate suggests it had actually taken place in 1969. Despite the intervening decade, it remains the earliest relevant reference to the greenhouse effect or climate change generally in parliament. Carbon Brief has contacted Hansard about this issue.
Analysis: The UK politicians who talk the most about climate change
Which UK politicians have talked about climate change the most?
Get a Daily or Weekly round-up of all the important articles and papers selected by Carbon Brief by email.
Expert analysis directly to your inbox.
Get a Daily or Weekly round-up of all the important articles and papers selected by Carbon Brief by email.