For years the debate about whether climate change is happening has raged on. However, the recent publication of the fifth report by the UN's Intergovernmental Panel on Climate Change is surely proof that that debate is over.

Prepared by more than 700 of the world top climate scientists from more than 70 countries over five years the content of Climate Change 2014: Impacts, Adaptation and Vulnerability is not alarmist, but still alarming. 

What are these scientists telling us? 

The world is warming and we are causing it by pumping carbon pollution into the atmosphere. As the world gets hotter, the atmosphere holds more water vapour. With each additional 1 degree of temperature the atmosphere can hold 7 per cent more water vapour.

So, although we can't say that climate change caused Hurricane Haiyan or Hurricane Sandy, scientists tell us that climate change definitely creates the conditions where a storm is more likely to become a devastating typhoon.

And those once-in-a-lifetime floods? Thanks to climate change they're happening now with increasing regularity, causing devastating death and destruction in short term, but also long term damage. 

Climate change is impacting global food supplies too. Basic food crops such as wheat and corn are at risk. This will lead to global shortage and steep price increases. Potential shortages of food and water also pose a threat to human security. They will likely amplify the already existing conflicts and may lead to migration of people whose supplies have run out.

Perhaps unsurprisingly, it is the vulnerable communities who will be affected most by climate change, particularly those who depend on agriculture for survival. It will also impact those communities with scarce water supplies.

As Christians, aren't we supposed to have good news for the poor? Certainly the part of the Gospel message about the world to come is a shining promise for those facing flooding and starvation, but what of today? How do we speak of God's Kingdom when people are facing extreme weather, food scarcity, and major damage to their homes and communities?  

Perhaps this is where the Prophet Micah would remind followers of Christ that we are called to "act justly and to love mercy and to walk humbly with [our] God"?

In humility we can recognise what the 700 are saying: that climate change is real and here and a threat to us all.

In justice we can decide to be the generation that takes action to reverse climate change. It is imperative that we cut emissions now, to slow global warming, as well as putting in place plans for sea walls, change of crops, irrigation systems and so on that can enable vulnerable communities to cope with the impacts of climate change. The technology for us to shift from fossil fuels to renewables exists. 

And in mercy we can reach out to those least able to cope with the impact of climate change by using our own skills, voice and resources to help them survive and thrive on our warmer planet. 

The Revd Canon Dr Rachel Mash is the Environmental Coordinator for the Anglican Church in Southern Africa