Two events last month have enormous implications for people across our planet. They had quite different agendas but both will help determine the kind of future the world faces.
Both events agreed that 2015 is the year by which far-reaching plans to meet some of the most urgent challenges must be agreed.
Both events also raised the question of whether governments can be persuaded to put competing interests aside, to make 2015 the year in which we save the world from climate disaster - with a coherent and aggressive approach to ending global poverty at the same time.
The first event was UN Secretary-General Ban Ki-moon's address to the UN General Assembly in New York. It marked the start of a new phase of discussions about the global plan which will replace the existing Millennium Development Goals (MDGs) at the end of 2015.
After a year of consulting far and wide on issues ranging from gender inequality, education and health to conflict, governance and economic growth and jobs, the UN will now move closer to establishing a new set of goals aimed at eradicating poverty worldwide.
The second of the two major events last month was when the UN launched the much-heralded 5th assessment report on the science of climate change from the Intergovernmental Panel on Climate Change (IPCC) .The report further confirms the certainty that climate change is man-made and underlines the crucial importance of the UN climate talks reaching an ambitious global climate agreement in Paris in 2015.
Although these might seem separate issues, the post-MDG process and the need to counter climate change are inexorably entwined. This gives us a huge opportunity to turn 2015 into the year the human race gets global development right, while averting disaster.
The IPCC report predicts that on current carbon emissions trends, the most optimistic outcome is a 1.5C global temperature rise this century. That would bring an increase in extreme weather events and risk the complete loss of many small island states.
More likely, however, temperatures will rise well above 2C, with potentially devastating global impacts.
Climate deniers, more than a few with vested interests in the fossil fuel sector, are already busy trying to undermine the report, presenting confused statistics which they claim expose global warming as a myth.
Evidence from Christian Aid's partners across the developing world tells a very different story. Their accounts show that climate change is already a reality and that without urgent action now, the outlook for some of the world's most vulnerable communities is extremely bleak.
The account of one Malawian farmer echoes those of farmers in many other countries: 'We used to have very stable rainfall that was adequate and non-erosive [did not wash away the soil]. These days no one knows when to plant crops.
'When rains come, they are either too little for planting or too heavy, so fields get waterlogged or eroded. A prolonged dry spell follows and scorches the germinated crops. The seed is lost.'
It is not just agriculture that is affected - climate change is affecting every aspect of development, with businesses ruined and education disrupted. During extreme weather events schools are usually closed, with some turned into emergency refuges.
Often it is women who bear the brunt of the resulting hardship, because activities they traditionally carry out are most affected - collecting clean water, and wood for fuel, and providing food for the family.
The impact of climate change on development must therefore be acknowledged in the new global development plan, with strategies that are resilient to climate change and ready for climate disaster.
One key factor it must address is whether the world is serious about keeping global warming below 2C.
This would mean an urgent shift to low-carbon energy - and confronting our consumption patterns.
The production, transport and processing of food, as well as food waste, for example, contribute almost 40% of global carbon emissions globally.
Companies have a responsibility, too. A recent survey showed that 50 of the 500 largest listed firms in the world are responsible for nearly three-quarters of the carbon production by all 500 and that their emissions are still rising, not falling.
A sticking point in both the climate and the post-MDG discussions will be the issue of equity. In simple terms, which countries should act first and deliver most, who should pay for it and how do we transfer technology from rich countries to poor?
It is imperative, therefore, that the two deals to be brokered are not seen in isolation but reinforce each other. A new vision for development is needed that guides both sets of deliberations and pulls them together. Only then will 2015 become a date to celebrate, rather than regret.