IAMA Professor of Climate Science who created the climate spiral and stripes graphics - AMA about science communication, global climate change, citizen science, and how you can help by showing your stripes tomorrow Friday 21 June!

Is there any emerging science that can possibly reverse any of the current warming trends?

Thanks for the question. First, reducing our emissions of greenhouse gases (mainly carbon dioxide) will reduce the rate of warming, but while we continue to emit those gases the warming will continue. However, there are also ways of removing carbon dioxide from the atmosphere, such as reforestation. If we wanted to reduce global temperatures then we would need to remove more greenhouse gases than we emit. Last, there are more dramatic actions which could be taken to artificially cool the planet such as putting giant mirrors in space, or by launching reflective particles into the upper atmosphere.

Hi professor, if we continue at the rate we are going, how soon will it take till we reach a point of no return. Meaning at what point will the damage be irreversible?

Also could we implement changes such as encouraging people to grow their own foods, such as microgreens, to limit meat consumption and gas usage to transport them?

Finally, how can I convince someone that climate change is real and not a myth?

There is no simple answer to the question about reaching no return. Simply put, the larger our emissions the more risks we face. We can reduce global temperatures by removing more carbon dioxide from the atmosphere than we emit, but this is not something we can do very easily. There are probably points at which we could trigger an irreversible event, e.g. melting of Greenland, but it is very uncertain when that could happen.

We could certainly do more local food growing which would reduce emissions from transport. As for convincing people, it depends on why they believe what they believe, e.g. is it a lack of information, lack of trust, or dislike of potential policies?

Dear Ed Hawkins,

Harvard Professor James Anderson says: "Recovery is all but impossible, without a World War II-style transformation of industry—an acceleration of the effort to halt carbon pollution and remove it from the atmosphere, and a new effort to reflect sunlight away from the earth’s poles. This has do be done, within the next FIVE years."

Article here: https://www.forbes.com/sites/jeffmcmahon/2018/01/15/carbon-pollution-has-shoved-the-climate-backward-at-least-12-million-years-harvard-scientist-says/

We thought so far, that reaching carbon neutrality in 2050 would be sufficient. Can you explain why our window of action has reduced to five years now?

Thank you very much.

Professor Anderson's views are not necessarily shared by everyone. I would not agree that we have to do all this within 5 years.

Hi! Can you please expand upon the kind of impact diet change could make? A lot of people seem convinced that changing their diet to be more sustainable is not going to make as much of an impact as, say, driving less. How powerful do you think diet changes will be in preventing rising temperatures, and do you think a top-down (governmental) approach would be more effective than individual change?

There is no one answer. We need to eat less meat, drive less AND do everything else to avoid the worst risks. See my response to LadyDerpington.

What are some common arguments you hear against the existance/severity of climate change? And do you have a quick reply handy for them if you happen to encounter someone who doesn't believe it's a real thing?

The most common argument I hear is that 'climate has changed before', implying that it therefore can't be our fault at the moment. I try to explain why this argument is wrong here: https://twitter.com/ed_hawkins/status/1120647542918787078?lang=en

Dear Prof Hawkins, how will average temperatures change in Iceland in 2050 and 2100 following the RCP8.5? Do you have a Link for me or the information itself?

The IPCC produced an Atlas of projected temperature change - the Arctic/Iceland is shown here: https://www.ipcc.ch/site/assets/uploads/2018/02/AnnexI_Fig8.png

The maps are for RCP4.5, but RCP8.5 warms a bit more by 2050 and roughly twice as much by 2100.

Thank you. I am sorry but I don’t know what the three columns stand for. 25% / 50% / 75% At which one do I have to look?

The 50% column is the best estimate, but there is some uncertainty, and the other columns give plausible lower and higher values.

Hi Prof. Hawkins -

First of all, let me say that I am a big fan of your work. What you have done over the past few years in innovative climate communications/visuals is amazing. Your work has provided the opportunity for so many new climate conversations.

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How have you seen people most effectively use the climate stripes to create effective climate dialogue? Any tips?

Also, I may have missed it, but do you offer stickers of the stripes for sale? I would love to see lots of climate stripes stickers on laptops--that would be an awesome trend we could start and a great springboard for more climate conversations...Just a thought.

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Please keep up the great work!

Thanks! Stickers are a great idea - not seen anything like that yet.

My favourite use is probably the person who painted his Tesla with the stripes:

https://electrek.co/2018/07/27/tesla-model-3-wrap-climate-change-awareness/

which is started a lot of conversations.

Can you speak a little more about geo-engineering - is it your opinion that we should do things like the examples you gave in a previous answer - put giant mirrors in space or launch reflective particles into the upper atmosphere? Or do you think it is too risky?

Great question. There are large risks from geo-engineering as we don't quite know that the consequences might be. For example, putting these reflective sulphate particles in the atmosphere is likely to change the circulation in the atmosphere and shift rainfall patterns. Also, geo-engineering only tackles the rise in temperatures. The other climate issue is that the oceans absorb some of our carbon dioxide emissions, which makes the ocean more acidic, causing problems for marine life such as corals. This ocean acidification can only be stopped by reducing our greenhouse gas emissions.

I love the spiral graphic and have pointed friends and family to it.

I have a pretty morbid question, please forgive the downer.

How long do you think Humanity, as we know it, has left?

That is, do you think we’re most likely to hit an extinction event, or all turn into cyborgs, or live in a radically different way... and when would that change happen?

I think it is unlikely that the human species will go extinct due to climate change - we can be very adaptable.. We are likely to see other vulnerable species go extinct however.

Thanks for the answer. Can I push you a bit further? Setting aside climate change being the catalyst for a significant change in Humanity, how long do you think we have left? Indefinitely, a few thousand, hundreds, or dozens of years?

Am sure we can survive for a very long time indeed - major asteroids, nuclear wars etc being the greatest risks to total extinction, in my view. But, we really should aim a bit higher than 'not extinction'!

Hi Ed Hawkins! I have a couple of questions regarding the need for a global shift to a “flexitarian diet” which requires us to eat less meat. 1. What are the measures taken to achieve this? 2. Are we going to see a huge global shift to a climate-friendly/plant-based diet in the future? Cheers!

Eating less meat, especially cows and sheep, will reduce emissions. This is because cows and sheep burp a lot of methane which is a greenhouse gas, and also because there is often deforestation to provide the land to graze cattle and grow feed for cattle. In the UK we are seeing so much more vegan food in shops and restaurants as people make choices to avoid meat and dairy products. Eating more local food will also reduce emissions from less transportation. Governments could choose to make policies to encourage more switching.

Hi Professor, I wanted to confirm I understand the stripes graphic - do the colors reflect the average temperature that year relatively to an average (the darker the blue, the cooler than average and vice versa) or simply the average temperature relative to the year prior (darker red meaning bigger jump from year prior but you can't compare a red on the right side to a red on the left)?

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Thanks!

Thanks. Each stripe is the average temperature in that particular year. The blue colours are for colder years than average and the red years are warmer than average. For these stripe graphics the average is set as the temperature during 1971-2000. As the colours change from blue to red from left to right, this shows the temperature in that location has increased.

Hello professor, I just wanted to ask how do we convince people and motivate them to be part of this, to try and make them change their life style for the climate?

Many of the actions people can take would save them money, e.g. using less energy, reusing more, walking or cycling more etc. That may be a way to start the conversation, rather than on climate change itself.

Hi professor, what are the top 3 research papers you would recommend to someone trying to quickly get up-to-date on climate science?

I would start with the summaries of the IPCC reports - http://www.climatechange2013.org or http://www.ipcc.ch/sr15 - to find the topics that interest you most. Thanks!

Do you think there still is hope?
Reading news about the permafrost, seeing how fridays for future ist just ignored in my country and how just a handful of people are changing their lifestyle makes it hard to belive we can do it.

I am confident that the worst impacts can be avoided. The UK has set an example by committing to 'net-zero' emissions by 2050 and this should encourage other countries to follow their example. Seeing the young people joining together in the climate strike movement is inspiring. Raising awareness of the issue is why we are launching #ShowYourStripes this week - our powerful and simple graphics can communicate our warming planet to a broad audience in as simple a way as possible. We need to talk about climate change and the potential solutions far more to our friends, family, colleagues.

Thankyou for this response. Maybe it's me, but it feels like almost everybody who doesn't deny climate change thinks it's going to wipe out humanity in 20 years. I feel like this kind of negativity is counterproductive as people just say "what's the use" and throw their hands up, instead of rolling up our collective sleeves.

I agree - in my view it is better to stress the positive changes that can be made rather than be too negative which can certainly be counterproductive.

It can feel very frustrating seeing all the research about climate change and feeling powerless to do much about it as an individual. What's the most beneficial thing an individual person can do? Do the little things (switching to bamboo toothbrushes, using reusable coffee cups etc) really make much of a difference?

Several things individuals can do:

1) Eat less meat and dairy

2) Cycle, walk and use public transport rather than cars (or use an electric car)

3) Fly less

4) Buy energy from a renewable source

5) Better insulate your house

6) Reduce waste, reuse and recycle

7) Talk about it!

8) Vote.

Isn't it safe to believe that the earth works on a cycle? And if that is so, then isn't what human beings are doing to the Earth inconsequential as the earth takes care of itself?

Yes, the Earth has natural cycles which work on timescales of many thousands of years, mainly due to variations in the Earth's orbit around the sun. Humans are changing the climate on the timescale of decades through emissions of greenhouse gases, and we've understood the physics of how that works since the 1850s.

Hey, what's your response to people that don't believe in climate change? Do you try to explain it to them and show them evidence, or do you think leave it because your probably not going to convince them?

It depends. Some people are genuinely confused and keen to learn, but many simply reject the science because the proposed policy options don't fit with their world views. Making climate change relevant for them is a challenge but discussing how it will affect them personally is often the best strategy.

Hi,

I am a bit confused about the calculation... as I understand, you used Z scoring right? Why the average of 1971-2000? Why not 1901-2018?

Thanks!

I chose 1971-2000 so that roughly half the warming occurred before then and half after. This maximises the numbers of colours being used for each location.

What would sustained action on the environment realistically do for global temperatures?

Sustained action to reduce emissions of greenhouse gases to zero would stop the planet warming further. To achieve this will require a transformation to society, infrastructure and personal behaviours.

Thanks Ed. Do you think that we can bring global temperatures back down, or are we going to only ever see the stripes red (or brown) from now on?

To reduce temperatures will require removing more carbon dioxide and other greenhouse gases from the atmosphere than we emit. This is technically possible but a long way from where we are today.

The more I see stuff about climate change, the more I get the feeling that the world is doomed. I've seen quotes stating that we have 12-15 years to become globally carbon-neutral or the damage is irreparable.

In my opinion, that just isn't feasible. Do we still have a chance, or is it simply too late?

If we want to limit warming to 1.5 or 2.0C above pre-industrial levels then we need to have halved our global emissions by about 2030 as a first step. But, the negative effects of climate change just get worse as temperatures increase. Although the policymakers have stated the desire to avoid warming above 1.5-2.0C, there is no sudden threshold, so 2.1C is not dramatically different from 2.0C.

Unfortunately, a lot of people don't like Al Gore (and call him a hypocrite for being wealthy and flying), so dismiss his message.
Aside from David Attenborough and Bill Nye there seem to be few well known mass communicators on climate science. We need people who ordinary citizens can relate to but also trust.

Who do you think could step up to this role?

Tricky question. Scientists play an important role and many are amazing communicators. But, we need a wide range of people involved as different communities tend to most trust people who are similar to them. There is no one person who would be trusted by everyone.

How do we know for a fact that the emissions by humans are causing the change in climate, and it’s not just a natural shift we’ve seen before?

The simple answer is: physics.

The basic physics and chemistry of how greenhouse gases interact with infrared radiation, which is the fundamental reason for the greenhouse effect, was first understood in the 1850s. There is no doubt that adding extra greenhouse gases to the atmosphere will warm the climate.

And, yes, the climate has changed before - we first worked this out in the 1820s. We also know the last century is different because of the speed and pattern of change.

I believe that the majority of people blindly follow... Climate change is the new Religion. Change my mind.?😳

Scientists use evidence rather than beliefs. We've understood there is a greenhouse effect since the 1820s, and the relevant physics was first demonstrated in the 1850s. We first realised the Earth was warming in the 1930s. There is nothing new about climate science. You can either trust us, as experts, who have studied this for decades, or not, but the fact is that we are changing the climate through our burning of fossil fuels and deforestation.

A lot of big initiatives right now seem to be aimed at global transformation-- replacing all gas cars with electric, building resilient infrastructure, retrofitting all the buildings, etc.-- but isn't all this activity incredible CO2 intense? Especially in areas that are providing electricity via coal, oil and gas?

How should we prioritize what we do, so we don't inadvertently add more CO2 to the atmosphere than we remove (especially in the short-term, when we may be facing a tipping point)?

The first step is to decarbonise the electricity supply as far as possible. This makes doing everything else much easier and less CO2 intensive.

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1) Millions of temperature measurements showing a long term warming

2) Millions of tide gauge records showing sea level rise

3) Satellites measuring Arctic sea ice extent show large decline etc

4) Photos of glaciers from over a hundred years ago showing larger glaciers then

5) Measurements of the natural world showing changes consistent with a warming climate

etc etc etc

That’s just the earth heating up again . It’s just cycles mate , get a life instead of fear mongering ?

There are natural cycles in the climate which occur over tens of thousands of years, but what is happening now is not one of them.

Hi Prof. Hawkins,

What would be your best guess of where you think we'll be in terms of temperature by 2100? Not in terms of current projections or what you'd like to see, but how you think action and progress will play out?

Personally my guess is that action is gradually ratcheted up so we do noticeably better than current projections, but not enough to stay below 2C, so ending up probably somewhere maybe 2.6/2.7C, but I'd love to hear what you think?

My personal view is that we will end up somewhere between 2.0-3.0C.

Have you noticed and increase in depression amongst your colleagues in light of the findings and the public's and government's underwhelming response?

Not noticed this personally.

Dear Professor Hawkins, how confident are you, that the IPCC's AR5 was too conservative in its projections and that AR6 will reveal some bad surprises for us? We can read about thawing permafrost at much deeper levels than the IPCC has expected, melting of ice sheets at higher rates than expected and so on. To my understanding, the concept of cascading tipping points was also not incorporated in the AR5 to its full extent. So how sure can we be, that our carbon budget is well calculated as everything seems to develop faster than expected. And finally, our likely chances to stay well below 2°C have been calculated with 67% chance. Why is that? 67% doesn’t seem very likely to me. When the life of my children depends on it, I would not be happy with a 67% chance. What would our carbon budget be to stay well below 2°C with a 90% chance?

The IPCC process is designed to review the whole of the literature and so if there have been well understood changes in certain parts of the climate system that are more rapid than expected then that will be evaluated and included. I am not allowed to comment on the specific contents of AR6 but the structure of the report has changed to better consider risks in certain topics. Carbon budgets to avoid reaching certain temperature targets are always calculated for a range of confidence levels - you can see the updates in the most recent IPCC Special Report: https://www.ipcc.ch/sr15/

Thanks for your answer. I am just wondering why is the basis for all public goals the 67% chance budget. Has anyone decided to go with 67% chance because this seems good enough? Why not aim for 90% chance or even higher? I don’t really understand this. Is it simply because it is impossible to stay below 2°C warming with a 90% chance?

My understanding is that policymakers asked for specific probability targets to be highlighted, though other probabilities are given in the text. I'm not certain as to why 67% was chosen.

It is not impossible to stay below 2C (or perhaps 1.5C) but we will need to reduce emissions quickly from now on to have a chance.

Thank you for pointing out that you are not certain as to why 67% was chosen. But may I ask you for your opinion as a scientist? To me 67% chance sounds not quite certain especially when it comes to such an existential threat as the climate crisis. This still means that with 33% probability, we will not limit warming to 2°C, even if we stay within the carbon budget.

What do you think about 67%? What chance would you regard as a sensible probability target? If you were counselling policymakers on that, what probability target would you suggest to use as a basis?

Thank you.

If I was talking to policymakers then the message would be that to avoid the worst risks then emissions need to be reduced to net-zero as quickly as is realistically feasible. The budgets are a useful tool but I'm not sure they are necessarily helpful for deciding policies - getting to net-zero is what needs to happen.

Is it tough to get up in the morning knowing you're living a lie? The earth is 45 billion years old and we have data from a fraction of a percent of the world's climate history. Ice ages and periods of warming prior to industrialization. How can you consider yourself to be anything other than a propaganda machine?

The climate has changed before. Why does that imply that the current warming cannot be due to human activity? That makes no logical sense.

In this case, we understand the basic physics - discovered in the 1850s - that certain gases absorb infrared radiation due to their chemical structure. Adding more of these gases to the atmosphere will warm the planet. This is 150 year old science which you are denying.

What are your views/opinions on chemtrails?

They don't exist. They are contrails.