Unintended consequences crop up throughout our lives; they can change our perspective, open new avenues and create all manner of problems. Science owes many groundbreaking discoveries to the unexpected but not all unintended consequences lead to great things - whether positive or negative the impact of the "unknown unknowns" cannot be understated. This edition of the environmental SCIENTIST seeks to highlight the uncertain nature of environmental science. In this issue we explore how historical and current policy making can lead to unpredictable outcomes, how a green energy solution solves more than one environmental issue and what happens when the native species return to their homeland to find an intruder.

As cities and towns nationwide look for innovative ways to tackle the housing crisis, land condition professionals dedicate themselves to unlocking land that was otherwise written off for development. With an increasing drive for accessible green space, remediated sites now not only provide much needed space for housing, but the chance for green spaces in the heart of our cities. This edition of the environmental SCIENTIST highlights some of the key challenges and opportunities currently being tackled by land condition professionals. This issue delves into the legislation surrounding land condition and land use, as well as how modern sustainability technologies and techniques are being incorporated into remediation practice.

As Higher Education Institutions increasingly strive to find the most impactful way of conducting innovative education and research, many are initiating Living Labs programmes. The objective of a Living Lab programme is to establish a platform where people from different stakeholder groups can easily and effectively collaborate. While Living Labs are not limited to sustainability, this sector has led the way and embraced their potential to enhance learning and employability for students, problem-solving for campus managers, and deliver real-world sustainability improvements. This issue of the environmental SCIENTIST explores the development of the concept, presents case studies from the perspective of a range of Living Labs stakeholders, and considers its potential to drive further change.

In September 2015, world leaders adopted the seventeen goals of the 2030 Agenda for Sustainable Development at a special United National Summit. 193 UN Member States signed up to the Goals, which are focused around ending poverty and hunger, protecting the planet, fostering peaceful societies and promoting partnerships to help achieve the sustainable development. Science is fundamental to many of the Goals and the 169 targets which accompany them, and this issue of the environmental SCIENTIST explores its role, in partnership with policy, business and civil society, in delivering on this ambitious agenda.

Though experts have been aware of the issue for many years, it is only in recent years that the majority of the media and public have become aware of the severity of the air quality crisis in many of Britain's towns and cities. But is it too little too late? The articles in this issue of the environmental SCIENTIST discuss controversial topics around air quality management and measurement, and suggest ways in which both government and individuals can strive to tackle this problem.