and bold claims about Covid-19 and how it's

changed human society forever.

But it's not easy to disentangle the things that

have changed for good from those that could rebound back

to normal or even beyond normal in the months ahead.

So I'm going to run through some of the predictions

that we've all heard about how Covid-19 is changing the world

and talk about which ones do and don't stack up

best against the data.

This year we've been introduced to V-shaped recoveries, U

shaped, Zs, Ls, and even Ws.

It's a lot to keep track of.

But the consensus for most western economies

is that things look pretty grim, and some countries

could be facing worst recessions than they had even

after the financial crisis.

The outlook for the economy is extraordinarily uncertain.

It is now, yes, very likely that the UK economy

will face a significant recession this year.

The picture in the UK, for example,

looks particularly bleak with the latest data showing

that the British economy may not recover to its pre-Covid levels

until sometime in 2023.

Now, even with the most creative handwriting,

I'm not sure that's a V. But there are other countries where

things look more positive.

The most striking of all of these is probably China.

And if we look at the data there,

we see that just 10 months after the country was in crisis,

China's economy is estimated to have grown by 1.8 per cent

over the year as a whole.

And with the economy fully back up and running,

including in Wuhan, it's forecast

to increase that to a growth of 8 per cent in 2021.

It's not just China either.

If we move further west to a place like Norway,

the economy actually rebounded more in the third quarter

than it had lost in the second and is on course only

to lose around 1 per cent of its GDP over the year of 2020

as a whole.

Positive examples like this do offer hope for countries

like the UK, suggesting that once the virus is

to an extent under control and, crucially, people feel

safe, certain sectors as well as the overall economy

can begin returning to something approaching normal.

When lockdowns brought cities to a standstill

the impact on global carbon emissions was profound.

In April alone, global emissions dropped by around 17 per cent.

And even over the full first half of 2020

they were down by around 9 per cent.

Since then, politicians have pledged

to build back better by bringing forward emissions cuts targets

and increasing their adoption of things like electric cars.

China has announced net zero emissions.

Net zero carbon emissions.

Net zero by 2050.

The European Green Deal will be our growth strategy.

This has raised environmentalists' hopes

that 2021 can be the first year of a new green revolution.

And the data have certainly provided plenty of examples

of what might be possible.

As the virus hit Europe and the US hard in March,

global commercial air traffic plummeted

by 80 per cent and city streets across much of the world

fell silent at the same time as stay-at-home orders

were rolled out.

But these patterns have not held,

and as public transport networks worldwide have either

been closed or increasingly seen as unsafe,

hundreds of thousands have flocked back to their cars.

As early as March, road traffic levels were back to normal

in many Chinese cities.

And even in London levels had returned

to their historical averages by September.

In the skies, there have actually

been signs of overshoot, suggesting

that people are responding to months of limited travel

options by throwing themselves into this even more

than they were before.

If we look at China, domestic air travel

has been at roughly similar levels

to the historical norm for several of the last months.

And indeed, in early October levels

exceeded what they'd been in 2019.

If these patterns that we've seen in China

are repeated elsewhere next year,

the hope for a flight free future

could be as far away as it's ever been.

One of the most frequently asked questions about the pandemic's

enduring impact is whether this can be the death of the city.

We've seen commercial real estate prices plummet.

And the millions of commuters, previously

the lifeblood coursing through cities' veins,

have vanished, putting at risk the many businesses that

provide for these people.

These temporary shifts will rebound in time, but exactly

how much is unclear.

Data on visits to leisure locations - cafes, bars,

restaurants, shops, and theatres -

show that although footfall recovered over the summer,

it increased more slowly in city centres than suburbs or rural

areas.

Even when people were out and about

they were near their homes, not their offices.

This has really got people thinking

about the whole future of commuting

and whether some people may indeed

make more permanent moves away from the bright lights.

But the great Covid-induced urban-to-rural migration

has been overstated.

And if we look at the data from the US on changes of address

this shows that there was only a 2

per cent increase in permanent moves in the first half

of 2020, and more than half of all moves were only temporary.

The figures also show that where people were moving out

of city centres, whether permanently or temporarily,

they were mainly moving to suburbs of those same cities.

Think Manhattan to Brooklyn, for example,

or to other major cities.

So to the extent that there has been some kind of urban exodus,

not only has it been relatively small scale;

it's mainly been people who were already

planning to move slightly further out,

just bringing that move slightly forward.

Unlike the threats of economic downturn and urban desolation,

one area where a lasting pandemic-induced change

would be more welcome is for people like us

in the western world to come out of this better prepared

for similar threats in the future.

A lot has been made of how countries in East Asia

learned from their experiences with similar infectious

viruses, like SARS or, in the case of South Korea,

MERS, about what it that is required to keep

a virus like this at bay.

It's become increasingly hard to deny

that a key factor for these Asian countries'

relative success was the fact that they acted quickly,

strictly, and early in doing things like ramping up testing

and putting on masks, whereas by contrast countries in the west,

generally speaking, were more slow to react.

But data from YouGov and Facebook

shows that mask wearing has been fairly widely adopted

almost everywhere in the world and that almost invariably

once people got used to wearing masks in public spaces

they kept doing so even during the virus's summer remission.

Since those figures apply equally

to countries east and west, north and south,

it suggests that next time the pandemic alarm sounds all of us

will be more ready, more prepared

to make the kind of quick changes

that can turn a months-long ordeal

into a short, sharp shock.

By its very nature data is backward

looking rather than forward, so I'm not

going to pretend that the charts, graphs,

and stats that I've shared with you today

can predict the future.

But that's kind of the point I'm making here.

As we all look ahead to what we hope

will be a much better year than 2020,

we should neither be too gloomy about the prospect

of further lockdowns or to naively optimistic

about this ushering in a new green era.

2020 could be a sea change, or it could just be a blip.

And all of us here will play a part in determining which.