The most robust scientific projections suggest changes we are already beginning to see will amplify, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems.
Before the end of this century, it is very likely heat waves will occur more often and last longer, and extreme precipitation events will become more intense and frequent in many areas. The ocean will continue to warm and acidify, and global mean sea level to rise.
If nothing is done, global warming would reach, on average, a sustained increase of somewhere between 4.1C and 4.8C above pre-industrial levels by 2100.
This figure is more than double what is considered to be dangerous to cross, as in, ecosystems cannot adapt safely to the change.
Here is the good news. The international community agreed to work on this problem nearly 25 years ago and at the end of last year, finally, a significant step towards solving the problem was achieved with the Paris Agreement.
This agreement was novel for four reasons. First, developed and developing countries agreed to contribute to solving the problem.
Second, it was accepted that financial assistance to the developing world was a quid-pro-quo and critical to get them on to a sustainable path, with US$100 billion a year required by 2020.
Third, unlike earlier attempts such as the Kyoto Protocol, which mandated a 5 per cent cut in greenhouse gas emissions for wealthy countries without reference to what was required to keep the planet from overheating, now, an ecological bottom line sets the basis for the target.
Thus, the signatories to the Paris Agreement committed to holding the increase in the global average temperature to well below 2C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5C above pre-industrial levels.
Fourth, the obligations are soft. Countries have adopted voluntary, non-binding pledges for which there is no penalty for non-compliance.
This allowed Barack Obama to pledge the US would aim to reduce its net greenhouse gas emissions by about 27 per cent below what they were in 2005, by 2025.
Similarly, New Zealand pledged a target of a 30 per cent reduction from 2005 levels by 2030.
Here is the bad news. First, climate change is moving faster than the national pledges. The 1.5C limit is already nearly impossible.
Recent evidence suggests we are already 1.1C higher than the pre-industrial period. Studies suggest the Earth will, as a best guess, cross the 1.5C threshold in 2024 and 2.0C in 2036.
Second, the pledges made so far are not sufficient, as when all added up, warming will still increase between 2.8C and 3.1C.
Third, revisiting the targets is already necessary as some countries, such as the US with Trump's recent changes of policy on energy, make it very unlikely they will achieve their pledge.
For others such as New Zealand, acrobatic accounting around the choice of baseline years, inclusions and exclusions, meant the final commitments promised were minimal.
The full extent of this became apparent recently when it was revealed that due to the Government's persistent failure to reign in our emissions to meet our Paris pledge, we will probably have to buy emission credits from other countries over the next 10 years to the value of $14.2 billion.
Finally, the international money to get the developing world on to a sustainable path is problematic, as not all countries are pulling their weight. For example, while Australia gave US$187 million ($7.92 per person), New Zealand managed only US$2.56 million (57c per citizen).
Moreover, Trump is threatening to walk away from the promise by his predecessor of US$3 billion ($9.41 per citizen).
Although the Paris Agreement should survive those who do not carry their fair share, it will be less effective.
