I have spent almost my entire working life in climate science and policy, social enterprise, government, and now philanthropy. Over time, I have seen public communication as increasingly important. Why? Greenhouse gas emissions need to decrease fast if we are to have any chance of keeping global temperature rises below dangerous levels, and it is hard to see how this will happen without greater, and more urgent, engagement with society. We need more people talking about climate change more often, because we need to break out of the current climate echo chamber.

However, many people feel under-equipped to do this. If that is you, these five tips may help you over this barrier. They are the result of both my own experience, and lessons from behavioural experts.

1. You don’t need (much) data

First and foremost, your primary task is not to tell people climate change is happening, or to make them worry about it. They already know, and they are already concerned. Despite what some media outlets and politicians would have you believe, public awareness of and concern about climate change is consistently high. Around two thirds of the US public worry about climate change “a great deal” or “a fair amount”, as they have done for two decades. In the UK, three quarters are concerned.

The challenge, then, isn’t awareness. It’s action. Concerns exist, but do not influence day-to-day decisions. Rarely is climate change a critical factor in elections. People tend not to think about climate change when deciding how to travel, how to invest their money or which energy supplier to use.

If you do come across the minority who are not aware, you still don’t need piles of data. You can communicate both the science of climate change and the urgency of mitigating it with some undisputed physics and three charts.

The physics: carbon dioxide and other greenhouse gases trap heat in the atmosphere. They absorb radiation from the sun which has been reflected off the earth, and then re-emit this radiation in all directions, reflecting some of it back onto the earth. This heats it up.

The charts:

a) Carbon dioxide levels in the atmosphere have increased far beyond any level seen naturally in the last 800,000 years. This increase has taken place since the start of the industrial revolution and is the result of burning fossil fuels. The increase is happening at a time when, naturally, carbon dioxide levels should be decreasing.

b) Since the start of the industrial revolution, global average temperatures have risen due to increased carbon dioxide in the atmosphere. Humans have already caused 1°C of warming.

c) We need to make dramatic changes right now to keep global average temperature rises below dangerous levels. To meet the Paris Agreement temperature goals, emissions must peak before 2020 and rapidly decline to zero.

2. Talk about what is already happening

Creating urgency is the real challenge. When trying to convey the urgency of mitigating climate change, it is tempting to focus on the dreadful impacts we are likely to see if we carry on emitting at current levels, because these sound big and dramatic.

But big and dramatic is often unhelpful. It can make the scale seem beyond what anyone can influence. Talking about things in the far-off future can seem so distant that it makes the whole thing unreal.

Instead, talk about what we are already experiencing. Seventeen of the 18 hottest years ever recorded have happened this century. Arctic summer sea ice is declining rapidly, at a rate of 13% per decade since the 1970s. Extreme weather events such as heatwaves, droughts and heavy rainfall are increasing in frequency due to climate change. These events lead to loss of lives and livelihoods, and social and political turmoil.

These facts are real, present and immediate. That’s how you create urgency.

3. Make projections personal

There are times when it is worth discussing projections, particularly for people in areas that haven’t yet been affected as much - because everyone will be.

If you do go into projections, get personal. Climate projections are typically communicated in averages, especially headline statements about increases in global temperatures. This masks a huge amount of global variability in impacts. If you’re to motivate people to act, getting beyond this and into the specifics of what they will experience is key. For example, if we carry on emitting as we are now:

- In Florida, sea levels will continue to rise, meaning king tides (the very highest) will flood further inland every decade, leaving houses uninsurable and potentially unsaleable.

- In Europe, heatwaves of the kind that occurred in 2003, killing more than 50,000 people, will become increasingly likely.

- In sub-Saharan Africa, a much higher risk of droughts will lead to insufficient access to drinking and irrigation water, and reduced agricultural productivity.

4. Namedrop others who acknowledge climate change

In all communications, the messenger is as important as the message. That’s why I’m writing this piece, because the world needs people like you to be talking about climate change, not just people like me who work on the topic. But that principle extends to what you say as well, because referring to others, particularly when they are surprising, is a powerful trigger. Messengers I like to introduce are:

- The world’s biggest oil and gas companies, which acknowledge the reality of human-induced climate change.

- Experts and decision-makers across the world, who say climate change is the biggest risk facing them (and have done for many years).

- Insurance companies, who assess risk as their business.

5. Give people meaningful agency

Finally, make sure that when you communicate about climate change, you give people ideas for what they can meaningfully do. The important word here is meaningfully: too many campaigns over-sell insignificant actions such as boiling less water in the kettle. Of course it makes a difference, but only a fractional one. People are not stupid; they know that cupfuls of hot water are not commensurate with climate change. This approach risks either diminishing the issue (“if boiling less water can solve it, then it can’t be that serious”) or diminishing the individual (“if that’s all I can do, I’m not going to do anything”).

The most significant elements of most people’s carbon footprint are travel and home energy use, so tackle the difficult stuff and talk to them about this, but recognize your responsibility too. Discuss what they can do as part of a collective - in their community or workplace, for example. Less obvious actions, such as changing your pension to a sustainable fund, can also make a big difference over time.

In the spirit of this final tip, then, let me end by giving you one thing you can do today. Have a conversation about climate change with someone you live or work with. Because ultimately, one conversation at a time is how we’re going to turn widespread awareness and concern into meaningful action.

Good luck!