Christiana Figueres has for many years been working to increase action on climate change around the world and currently heads up the UN Climate Change Secretariat, or UNFCCC. Right now, as the UN’s top climate change official, she’s working hard to support governments in reaching a transformative global climate change agreement in Paris at the COP21 UN Climate Change Conference, in December. This week, Christiana Figueres answered questions via the internet platform Reddit about climate change, the international process towards a new, universal climate agreement and the amazing groundswell of global climate action we are seeing.

Here are 10 important things she had to say during the Reddit "AMA" (Ask Me Anything):

1) "I’m optimistic about getting an agreement in Paris"

I am optimistic for Paris. We have so much momentum going into this conference from the past 5 years of progress in the negotiations and from the businesses, investors, cities and regions that are already engaged in climate action. The greatest barrier to success will be in the details – how the interests of all countries will be reflected in the final text and decisions. Also, finance and technical support for the transition in developing countries will be a big challenge.

2) "National climate action plans are blueprints for investment"

All of the INDCs, or national climate plans submitted by 155 countries now, are potential blueprints for investment, each country having identified the sectors that are priority for them. There is much interest now in helping particularly developing countries take these proposals for policies and measures to the point where they can become investment plans. With $90 trillion set to be invested over the next 15 years in infrastructure and energy there is much potential!

3)  "The 2 degrees Celsius temperature goal is achievable"

I have been pellucidly clear that the agreement in Paris is not going to reach a 2 degree limit on temperature rise as though that were something we can take off a magical shelf and put on the table. I have been equally clear that getting us on to the 2 degree pathway is entirely possible. This is why the Paris agreement will have two very important components with regard to emission reductions: First, it will harness all the national climate change plans which as a group, if fully implemented, already substantially reduce the business as usual growth in emissions. Second, in recognition that this first set of INDCs (the national climate action plans) is a departure point and not a destination, the Paris agreement will construct a path of ever-increasing emission reductions with periodic checkpoints of progress until we get to the 2 degree pathway.

4) "Every country, including the smallest, has a role to play"

Given its extremely clean energy generation, Costa Rica is one of the world’s lowest emitters. However, that has not stopped Costa Rica from assuming its responsibility to identify the mitigation contribution it can make in addition to identifying the urgent adaptation measures it must take. The bottom line is that every country can and must contribute in the way that makes the most sense to them given their natural resource base, geographic location, emission reduction potential and vulnerability.

5) "Civil society needs to encourage government ambition"

The role of civil society in continuing to encourage ambition expressed in both environmental integrity and social fairness is critical to all our negotiations. At the same time, the UNFCCC is an intergovernmental treaty body designed for the purpose of governments reaching common ground with each other. Over the past 5 years, we have consistently increased the transparency of the intergovernmental process by providing constant and timely information about the proceedings on our website and by encouraging frequent and open stocktaking plenaries. We have also not only allowed but frankly even supported actions on the part of civil society representatives as long as they stay within the agreed rules of conduct.

6) "We’ll have a lot more climate refugees if we don’t act now"

If we do not do our job properly, we will have painful situations of forced migration. Perhaps to a scale we cannot even imagine. That is precisely why it is so urgent that we agree on a path to reduce global emissions within the boundaries of science.

7 "Future cities need to look more like gardens and less like Lego-scapes"

The expansion of urbanization and growth of cities in the future is well known. What is less understood is how we can plan and develop cities that are more organically grown and lived in than built and operated. If we look at future cities from the atmosphere’s perspective lived-in gardens, not expansive Lego-scapes.

8) "The use of nuclear energy is an issue each country needs to decide"

The use of nuclear energy is a decision that is and remains a sovereign responsibility of each country. It is clearly a non-GHG emitting source, however in its use every country will have to consider the other potential consequences as well as the rising cost of additional safety measures that have now been proven to be necessary.

9) "Even high emitters like myself can go carbon neutral"

I am very conscious that I am personally a high emitter given the air travel that I have to do for my job. As long as I have the responsibilities that I do, I have to incur these emissions but that will not be my lifestyle forever. In the meantime, in order to be climate neutral and support mitigation and adaptation projects in developing countries, I have purchased Certified Emissions Reductions from the Adaptation Fund using the Climate Neutral Now program and I encourage everyone to do the same, as well as making low-emission lifestyle choices.

10) "I stay focused for the sake of my children – and all other children"

I don’t get depressed but I do get frustrated with the pace of progress. I stay focused because of my daughters and all the sons and daughters to come.

See the full conversation on Reddit