Do-it-yourself biology, genome editing and hunting for aliens might sound like storylines from a science fiction film. 

But they are just a few of the issues on the agenda at the World Science Forum taking place in Budapest this week. 

More than 1,000 leading scientists, policymakers and journalists from 120 countries and regions are attending the event, which only takes place every two years.

The main theme this year centers around ethical problems scientists face as technology moves ahead in leaps and bounds.

The event takes place at the Academy of Science, a 19th century landmark building on the banks of the Danube river in central Budapest. But discussions focused on the role of ethics in 21st century science. 

One of the pressing issues is genetically modified babies. Last year, Chinese scientist He Jiankui claimed to have created the world's first genetically modified babies to make them resistant to HIV, causing widespread outrage. 

Some scientists argue this type of gene editing should not be attempted yet because it could make permanent changes to DNA that could affect future generations or cause harm if other genes are affected.

Some worry it will be used to design babies with desired traits.

China's representative at this year's Forum was Li Zhenzhen from the Chinese Academy of Sciences Institute of Science and Development. She was one of the panel speakers on the topic of the "ethical conduct of science." 

"In the past, our genes determined the evolution of human beings. Now we must be cautious, because by altering babies there is a risk that we could be altering mankind," she said.

But opinions on this matter are divided.

"I think that sometimes it could be permissible to genetically modify babies, so, for example, if you have Tay-Sachs. And you can actually edit out the gene for Tay-Sachs, which is a very debilitating disease, it seems like it would be permissible to do that. It raises further issues, such as do we want intelligent or athleticism or beautiful babies, that's where ethics, that's where we should be thinking about these issue," said Matthew Liao, director of the Center for Bioethics at New York University.

These are challenging times for science, amid a rise in fake news, which has made ideology appear to be more important than scientific evidence.    

This year has seen countless examples of natural disasters, from floods in Venice to wildfires in Australia and California. Yet, there are still people who deny climate change exists. 

It's a problem that many scientists and policymakers, such as James Gillies, are finding hard to counter. He is the Geneva-based senior communications advisor at CERN, the European particle physics laboratory.

"I wish I knew how to counter that, it is indeed a very big question. How do you get away from the idea that opinion counts more than fact these days? That's a real, real challenge," he said.

The Oxford English Dictionary now has an entry for the expression "Post Truth," which it defines as circumstances in which objective facts are less influential in shaping public opinion than appeals to emotion and personal belief.

Other ethical dilemmas facing the scientific and wider community include euthanasia and the use of artificial intelligence.