We can't escape the fact that throughout history countries are most carbon-intense and least sustainable on their way to becoming rich; not when they get there. So if the message to developing countries is that they are not allowed to develop in the same way as rich countries developed... are we sure that they will sign up to this?
Sierra Leone should be one of the most prosperous countries in West Africa, with its diamonds, iron ore and bauxite reserves. Yet, the vast majority of its people live in grinding poverty, and the country has the fourth highest maternal mortality rate in the world. On health, though, it is making progress.
Poverty has always been with humanity - even Jesus said that the poor would always be with us. Yet while nothing short of a miracle would have made poverty eradication possible 2,000 years ago - neither emperors nor kings had the knowledge or resources to do it - today, we have what it takes to tackle poverty.
The goal of extreme poverty reduction is surely the best-known of the UN's eight Millennium Development Goals (MDGs). On the face of it, target 1a - to halve, from 1990 levels, the proportion of people living on less than $1.25 a day by 2015 - is seen as a success story of the MDGs project, having been achieved five years ahead of schedule.
As the 2015 end-date of the MDGS draws near, a puzzle remains: why has the target on clean water been surpassed, while progress on sanitation has been so poor? Surely water, sanitation and hygiene (WASH) go together? This question goes to the heart of the MDG worldview, and the problem of measuring development generally.
With global economic uncertainty still with us, and sovereign states struggling and cutting back on their spending, expectations of philanthropists, charities and aid agencies are immense. We are trying to practise cost cutting and to find new ways of helping because we are frustrated with the old ways.
The support of multilateral agencies for basic education is slowing compared with other sectors and bilateral donors. Unless multilateral aid is increased, there is a danger that growing support to new areas such as skills development will squeeze the scarce resources for basic education even further, to the detriment of the most disadvantaged.
Globally, women and girls are estimated to account for almost two-thirds of the people who live in extreme poverty. Women currently perform two-thirds of the world's work and produce 50 percent of the food, yet earn only ten percent of the income. To add to this injustice, only one in five parliamentarians worldwide is a woman.
I believe we have reached a watershed moment on disability - one which we cannot afford to get wrong. Development progress is only as good as the weakest member and progress made across the world is diluted if the most vulnerable are left behind. If developing countries are to move forward into prosperity and greater self-reliance, they must take everyone on the journey.
This week marks 100 days since the report of the high level panel on the Post-2015 Development Agenda. As eminent persons and development academics once again turn their thoughts to what will replace the Millennium Development Goals (MDGs), it's worth remembering what these debates really mean for mothers and babies in Sub-Saharan Africa.
The United Kingdom, which is now the largest bilateral donor to basic education in sub-Saharan Africa, has shown admirable leadership in meeting aid commitments and making basic education a high priority. Having assumed the presidency of the G8 this year, we encourage the UK to ensure that other G8 countries follow its lead.