Global growth is being deeply affected by the trade turmoil fomented by U.S. President Donald Trump and uncertainty is at the forefront, with slower growth in many places and plenty of policy risk. Here are five key issues to watch in 2020.

Expect little overall improvement in global economic prospects. It would be unrealistic to expect a material improvement in economic performance. Both the International Monetary Fund and Organization for Economic Co-operation and Development project the global economy will not strengthen by much; growth in 2020 will remain below 3.5 per cent, after 3 per cent projected for 2019. That would be the weakest period of global growth since the 2008-09 financial crisis and recession.

As of mid-December, the World Trade Organization’s judicial arm has ceased to operate, an ominous forewarning that extends beyond the WTO itself – a sign that the global order, such as it was, is undergoing seismic shifts. The immediate issue may be at the WTO, but the root cause is the global confrontation between the United States and China, extending beyond Geneva with broad geopolitical implications.

The paralysis of the WTO’s dispute settlement system is due to Washington’s refusal to agree on appointments to the Appellate Body – either to reconfirm the appointment of members whose terms have expired or to appoint new members. That body is a vital part of the multilateral system that hears appeals of lower WTO panel…

Starting Dec. 16, the Alberta Court of Appeal will hear arguments regarding the constitutionality of the federal Greenhouse Gas Pollution Pricing Act – the so-called carbon-pricing “backstop," under which Ottawa would impose a price on greenhouse gas emissions in any province where it deemed provincial measures are not sufficiently stringent. The Alberta government’s challenge to the federal backstop is just the latest in a months-long string of appeals-court processes by governments in Ontario and Saskatchewan, where the legislation was upheld; those appeals are now headed to the Supreme Court, which will begin its hearings in March.

So the legal arguments being deployed feel, at this point, quite well-trod. However, the federal…