According to a recent poll, every third person living in Hamburg wants to leave the city during the G20 summit on July 7-8. Their decision is not surprising: who is crazy enough to be in a city with Trump, Erdogan, Putin, Merkel and the Saudis, 20,000 policeman and most likely 100,000 people protesting on the streets?

When the last G20 summit took place in Hangzhou, a city with more than six million inhabitants, China found a brilliant solution to this problem. Weeks in advance of the 2016 G20 summit, where China announced its decision to ratify the Paris Agreement, the Chinese government declared a week-long holiday and encouraged citizens to leave the city.

After the trouble-free summit in China, the person who pointed to the map of Germany and said, "Let's do the next G20 in Hamburg!" must not be exceptionally bright. With a long leftist tradition and strong activist presence, Hamburg is probably the city most unlikely to host a problem-free summit like the one in Hangzhou.

The grievances of the local population aside, there is a good reason to think this summer's G20 summit will be the most important international political event of the year.

First of all, after Donald Trump's decision to withdraw the United States from the Paris Agreement, difficult and unpredictable negotiations will have to take place during this year's summit.

Second, after the terrorist attacks in London, British Prime Minister Theresa May called for global internet regulations and Germany's Angela Merkel and France's Emanuel Macron soon followed her lead. The three "leaders of the free world", or also known as MMM, obviously want to use the G20 to push for more restrictions on internet freedom.

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Third, the Saudis are also going to attend this summit, and most probably they are going to push for new arms deals.

And last but not least, there is the possibility of the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) making an appearance. No wonder Germany reintroduced border checks before the G20 summit and the US is planning to deploy in the city Predator drones, which are usually used in warzones.

Even if you overthrow a political system that is imposing austerity and wars, the real question is what do you do the day after, how do you run the economy and organise daily life.

So if Hamburg is going to become a sort of warzone, a heavily militarised city under a "state of emergency", the question which all progressives have to ask themselves is: What can we do differently this time?

Before the G20 summit in Hamburg, if one thing is clear from our past experiences of mobilising and protesting, it is that the main models of resistance are obviously not enough anymore.

The model of alter-summits, inspired by the spirit of the World Social Forum, is still necessary in order to gather and exchange experience and ideas (what the entrepreneurs would call "networking"), but unfortunately, it does not have the capability of really challenging the G20. In other words, counter-summits are necessary, but they don't have the power to disturb the G20 and whatever deals world powers would be able to conclude during the summit.

The model of massive public demonstrations is also necessary in order to show the massive dissatisfaction with the current global system. But even if there are 150,000 people in the streets, this massive mobilisation won't produce any concrete change.

If the demonstrations in 2003 of more than 10 million people in 600 cities against the invasion of Iraq couldn't stop the war, why would a mass protest in Hamburg be able to make any difference? The power brokers of today's world order, which caused several wars and the rise of ISIL, will be in Hamburg - Theresa May, Donald Trump, and the Saudis. But wars, unfortunately, can't be stopped by mere protests in the face of those who lead them - whether peaceful or violent.

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Even if protests or a mass uprising are able to overthrow a political system that is imposing austerity and wars, the real question is what do you do the day after? How do you run the economy and organise daily life? Our action at the G20, therefore, should not be only about disobedience. It should also be about proposing a viable alternative for the day after.

This is why beside disobedience we need something that we at the pan-European movement of democrats, DiEM25, call "constructive disobedience". It is not enough to say "No" or protest. It is not enough to meet and discuss, criticise or disobey by enacting violence.

To be progressive and constructive, disobedience must be accompanied by counter-proposals fully outlining alternative policies to the ones that we disobey.

What does this precisely mean in the context of the upcoming G20 summit in Hamburg? Just take the three main battlegrounds: climate change, internet freedom and arms trade.

Our solution to climate change would not be condemning Trump's withdrawal from the Paris Agreement, as the agreement itself does not constitute serious enough action. Our solution would be to demand complete carbon divestment, thus re-directing further energy investments from unsustainable fossil fuels into clean energy, accessible equally to all European citizens. In doing so, we should, following the examples of "rebel cities" such as Barcelona or Naples, urge for democratising energy governance systems allowing European citizens direct say in how energy resources are managed.

Given that the internet is already a panopticon of surveillance capitalism, owned and controlled by an oligarchy of Silicon Valley corporations, and given the ongoing threat against our digital civil liberties in the name of fighting terrorism, our "constructive" proposal should be a blueprint for the Internet of the People based on protecting human rights and the "digital commons".

When it comes to the sale of weapons to repressive regimes, which consequently facilitate terrorism, the "constructive" proposal should go along the lines of the recent Labour Manifesto which explicitly states it would block the sale of weapons to Saudi Arabia.

Finally, in order to achieve a positive disobedience, we must look to create a new Non-Aligned Movement, which would work towards implementing these constructive policies. In the very likely case that the establishment represented by the G20 rejects these proposals, then it will be time for disobedience.

If our constructive proposals encounter the usual "there is no alternative", then we shall disobey. The G20 is already suffering from major divisions and we should exploit that. We should be united in putting forward a real alternative.

Srecko Horvat is a philosopher from Croatia. His latest books include "Subversion!" and "The Radicality of Love" (2015) translated into more than 10 languages. He features in Al Jazeera's documentary film "Europe's Forbidden Colony".

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.