An important international meeting about climate change took place in Bonn, Germany earlier this month. Attended by more than 10,000 delegates, it received relatively little attention in the world’s press – with some exceptions – but it laid down an important marker in global politics. Climate change shows every sign of becoming the defining issue of our time. So what are the key updates?

Q. Yet another climate meeting – what was it all about?

Bonn was the 23rd UN Conference of the Parties (COP23), an annual international meeting to agree plans to address climate change. Two years ago, the COP meeting in Paris made history by establishing an agreement among the nations of the world to prevent global warming of more than 2 degrees by the end of the century – and 1.5 degrees if at all possible. Bonn represents the next phase of the project.

Q. In what way?

The purpose of the Bonn meeting was to draw up rules and guidelines to implement the Paris Agreement, due to come into force in 2020. This amounted to each nation agreeing to a roadmap to achieve necessary reductions in greenhouse gas emissions across different sectors such as agriculture and transport.

Q. Yet the US is pulling out of the Paris Agreement?

Yes, US president Donald Trump has declared that he will remove the US from the Paris accord. It’s disappointing, but no great surprise. For many years now, most Republican senators have refused to accept the scientific verdict of a link between greenhouse gas emissions and climate change. Since the election of Trump, we have seen the appointment of fossil fuel advocates and climate sceptics to almost all key US governmental positions concerned with the environment, so the withdrawal of the US from the Paris Agreement was predictable. In fact, the official US delegation at Bonn hosted a meeting extolling the virtues of coal.

Q. Won’t the loss of the US scupper the Paris Agreement?

Ironically, the White House stance seems to have concentrated political opinion like never before. Another urgent prompt is that we are beginning to experience the first effects of climate change manifest as an increased frequency of severe storms, heat waves and flooding around the world. Now that the general public are beginning to take the issue more seriously, politicians will follow.

Q. And the media?

It’s curious that climate change shows every sign of becoming the defining issue of the 21st century, yet media coverage of the issue remains sporadic – compare the media coverage of global warming with that of Brexit or of Trump’s tweets. Worse, large sections of the tabloid press have been peddling climate scepticism for years. However, the public mood is changing and will change further as global warming manifests itself.

Q. What about Ireland?

There’s no denying that Ireland’s emissions are increasing, not decreasing, in major sectors such as transport and agriculture. Indeed, we are currently ranked lowest of all European countries in terms of our action on climate change. In addition, a recent Government plan to address climate change lacks the specific targets needed to achieve cuts in emissions.

Q. Aren’t we bound by EU targets?

We are, but we will probably miss our 2020 targets and face a hefty fine instead. You can expect this to be portrayed as Brussels bureaucrats imposing unreasonable targets. In fact, the EU is playing a very important role in co-ordinating action on climate change, yet another reason why Brexit seems a very bad idea.

Q. We’re hardly the only ones?

That’s true, but not much of a consolation. The latest studies suggest even if each country meets its commitments under the Paris Agreement, our planet will likely warm by more than 2 degrees by the end of the century, the limit beyond which impacts of climate change are expected to become very severe.

Q. How trustworthy is that forecast?

There is no doubt the earth’s climate is sensitive to certain greenhouse gases in the atmosphere, and no doubt an increase in the concentration of such gases is beginning to have an effect. If the phenomenon continues unchecked, we can expect a continuing rise in surface temperatures and sea levels, resulting in increased drought in many parts of Africa and increased flooding in many parts of Asia, to mention just two outcomes. We can also expect a rise in political instability in climate-vulnerable regions, accompanied by a global refugee problem, so it’s not a problem we can ignore.

Dr Cormac O’Raifeartaigh lectures in physics at Waterford Institute of Technology and is a fellow of the Royal Astronomical Society