When it comes to "building back better" for the world, the most ambitious blueprint is the set of sustainable development goals (SDGs) established by the United Nations in 2015, which 193 member countries have endorsed.
The idea was to tackle the world's most pressing problems, such as poverty, inequality, climate change and access to education. There are 17 broad goals, each of which has multiple targets that must be met for the goal to be attained. In all, there are 169 targets. The deadline for achieving them is 2030.
Backsliding after Covid-19
Even before Covid-19, the world was falling well short of achieving most of the goals on time.
But the pandemic has led to further backsliding on a massive scale. For example, goal No. 1 is to "end poverty in all its forms everywhere".
Pre-Covid-19, projections showed that about 6 per cent of the world's population - or about 470 million people - would still be living in extreme poverty by 2030.
But in a report last December, the UN Development Programme (UNDP) projected that as a result of the long-term effects of the pandemic, an additional 207 million people would fall into extreme poverty by 2030.
In January, the World Bank estimated that Covid-19 has already pushed 119 million to 124 million people into extreme poverty. These numbers are likely to be underestimates as they do not take into account the impact of the recent surges of Covid-19 in India, parts of East Asia and Latin America - and the pandemic is far from over.
The SDGs relating to health have also gone way off track.
Health services have been disrupted everywhere. About 70 countries have suspended childhood immunisations, and treatments for non-Covid-19 diseases have had to be deferred.
Progress towards SDG No. 4 - to achieve inclusive and equitable access to education - has been reversed.
UN agencies estimate that about 1.25 billion students have been affected by lockdowns and 86 per cent of primary school pupils in developing countries - most of whom have little or no access to online learning - are missing out on education.
Income inequality has risen even in rich countries as lower-income groups who cannot work from home have been the worst hit by lockdowns and social distancing requirements. Gender inequality has also worsened as the burden of unemployment and increased childcare needs has fallen disproportionately on women.
SDG No. 8, which seeks to create "full and productive employment and decent work for all", has become harder to attain.
The International Labour Organisation estimates that 1.6 billion people - about half of the world's workforce - work in the informal sector, where job losses have been massive.
Goals relating to environmental sustainability were missed even before Covid-19 and there have been few improvements since, as many countries have been forced to divert resources away from initiatives to fight climate change.
Scaling back ambitions
With so many SDGs looking increasingly unattainable as the pandemic rages on, social scientists are debating whether they should be revised or even scrapped.
The goals and their 169 associated targets were controversial even before Covid-19. For example, in a commentary titled The 169 Commandments soon after the SDGs were announced in 2015, The Economist trashed the project as "sprawling, misconceived and unfeasibly expensive".
It recommended that the list of goals should be shorter, aimed at ending poverty, boosting education and improving health.
After the outbreak of Covid-19 and the resulting economic and social devastation, the criticism of the SDGs has intensified.
The critics' main point is that the SDGs have now become unachievable. What is needed is a scaling back of ambition and a reordering of priorities.
Writing in Nature magazine, research scientists on conservation Robin Naidoo and Brendan Fisher argued that some goals and targets have become more urgent in the light of Covid-19.
Priority should be given to those that lessen the chances of future pandemics, such as reducing the trafficking of wildlife and the supply and demand of illegal wildlife products.
Health-related goals have also become more important.
Achieving universal health coverage, boosting the ranks and skills of health workers and strengthening early warning systems for global health risks would cushion the impact of Covid-19 on poor countries.
The scientists also propose that countries should focus on improving well-being rather than boosting gross domestic product growth, which may also conflict with sustainability goals.
In defence of SDGs
While these criticisms may appear pragmatic, they have met with pushback from several economists.
The SDGs should not be up for revision, they say. In fact, they are now more relevant than ever and are a guide path out of the crisis.
Just because there is a crisis does not mean the SDGs have become less urgent - quite the opposite.
Indeed, had more attention been paid to SDGs - for example, to one of the targets under SDG No. 3 which calls for "early warning, risk reduction and management of national and global health risks" - the impact of the pandemic would not have been so severe.
Some economists maintain that the SDGs are both feasible and affordable.
Professor Jeffrey Sachs, Dr Guido Schmidt-Traub and Mr Guillaume Lafortune of the UN Sustainable Development Solutions Network - which mobilises technical expertise in support of the SDGs - point out that the main problem is the failure of rich countries to honour the goal of international partnership (SDG No. 17) as well as failures in international cooperation and domestic governance in many countries.
There are pathways to achieving the goals, through transfers of public funds and the right kinds of investments.
As for affordability, the International Monetary Fund and other agencies estimate that the SDGs can be funded at a cost of about 2 per cent of global GDP, supplemented by 0.4 per cent of GDP in development aid to fill the funding gaps in poor countries.
In short, the problem is not the SDGs, but the lack of political will.
And so, Messrs Sachs, Schmidt-Traub and Lafortune suggest that "rather than abandoning goals that reflect basic human rights and ignoring the need to respect earth's planetary boundaries, experts should uphold the SDGs and speak truth to power about what is needed to achieve them".
Global, not local, solutions
So, what are the chances that the SDGs will get more attention and funding and, therefore, traction in the wake of Covid-19?
So far, not so good. Up to now, responses to the pandemic have largely taken the form of "my country first" policies.
Rich countries have launched huge stimulus packages to shore up their own economies, paying scant attention to the plight of poorer countries.
They have also mostly cornered the available vaccines, buying up more than they need. This may be politically understandable, but it reflects an insufficient recognition of the fact that a global pandemic cannot be tackled only locally.
The resurgence of Covid-19 in countries that thought they had it under control is a reminder that as long as the coronavirus festers and mutates anywhere in the world, there can be no assurance of safety or a return to normality, even for rich countries.
Withholding support from poorer countries may have been feasible in normal times, but it is not an option amid a global pandemic.
That support would need to be designed not only to bring Covid-19 under control, but also to build economic and social resilience and ensure that countries are able to develop sustainably if negative spillovers to other countries are to be avoided.
The SDGs provide a masterplan and already have the buy-in of all countries.
Providing funding and the technical assistance to achieve them - even if some achievements fall short of targets - would be the best chance to "build back better", which has to be a global project.
And so, far from scaling back ambitions, some observers suggest that countries need to dramatically enhance them.
Mr Angel Gurria, previous head of the Organisation for Economic Cooperation and Development, Mr Jeremy Grantham, a legendary fund manager and champion of sustainability, and Oxfam International, among others, have called for a new version of the Marshall Plan, which rebuilt Europe after World War II - except that this would be focused on rebuilding the world.
The pandemic is a tipping point, says UNDP administrator Achim Steiner, "an opportunity to invest in a decade of action that not only helps people to recover from Covid-19, but that resets the development path of people and planet towards a more fair, resilient and green future".
Or, as the writer Arundhati Roy puts it, the pandemic is "a portal, a gateway between one world and the next".
If that is true, the SDGs - as lofty and ambitious as they are - may be exactly what the world needs.
The 17 sustainable development goals
1. End poverty in all its forms everywhere
2. End hunger, achieve food security and promote sustainable agriculture
3. Ensure healthy lives and ensure well-being for all, at all ages
4. Ensure inclusive and equitable quality education and promote lifelong learning opportunities for all
5. Achieve gender equality and empower all women and girls
6. Ensure availability and sustainable management of water and sanitation for all
7. Ensure access to reliable, affordable, sustainable and modern energy for all
8. Promote sustained and inclusive economic growth, full and productive employment and decent work for all
9. Build resilient infrastructure, promote inclusive and sustainable industrialisation and foster innovation
10. Reduce inequality within and among countries
11. Make cities and human settlements inclusive, safe, resilient and sustainable
12. Ensure sustainable consumption and production
13. Take urgent action to combat climate change and its impacts
14. Conserve and sustainably use the oceans, seas and marine resources for sustainable development
15. Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification and halt and reverse land degradation and biodiversity loss
16. Promote peaceful societies for sustainable development, provide access to justice for all and build effective, accountable and inclusive institutions at all levels
17. Strengthen the means of implementation and revitalise the global partnership for sustainable development