The greatest issues are happening on local scales and are therefore difficult to identify by individuals. But certainly I would include 1. Plastic in waterways and oceans 2. Collapse of fisheries 3. Rehabilitation of mine sites and post- industrial land 4 Palm oil plantations 5 Agricultural pollution (especially sediment and nutrients). 

Ocean acidification is will change the earth in unforeseeable ways but it's not an acute problem.

I believe that the most pressing ecological question is "Are we sustainability managing the planet's ecosystems or are we committing whole scale ecocide?"  

I love your question. Well, in the next five years

1. Which species of aquatic/ terrestrial animals may be extinct?

2. Will ecological degradation be higher or lower?

3. Will sustainability of the ecology have been realised?

4. What new forms of pollution can we encounter in the ecological environment with the continuous advent of technology?

5. Will the human populace have come to terms with the increasing level of ecological degradation?

6. Will the human populace be well informed enough to stop or decrease activities that destroy the ecology?

Thanks, I think that there is a lot of crossover already, and the focus of sustainability and concepts of degradation, encapsulated in the 'endgame'of ecocide is very powerful. I feel very much in line with these ideas. Desmond, I fear that the answer to your question  5 is very much a No, until perhaps it is far beyond a situation that we can remedy. Unfortunately, our species is not very good at looking beyond the immediate future...

The greatest issues are happening on local scales and are therefore difficult to identify by individuals. But certainly I would include 1. Plastic in waterways and oceans 2. Collapse of fisheries 3. Rehabilitation of mine sites and post- industrial land 4 Palm oil plantations 5 Agricultural pollution (especially sediment and nutrients). 

Ocean acidification is will change the earth in unforeseeable ways but it's not an acute problem.

In thinking to the futur of the faraway evolution life.

The deep complexity of mind and/or brain reached in the human species, can develop in more and more intelligent robots. those robots which will have a more deep conscience than human in the futur times and then could develop an intelligent super- brain. In this case others projets could be planned with a non-carbon life, like silicon or other atoms giving a new life for a far long time to come. "Material toward the life: is chemistry". or equivalency: "Material toward life: to reach up a progress in a more intelligent world".

Really challenging question; but I wish to express my view point in this regard:

I think, the ecological issues are not very many, but just one, because all the ecological issues are quite interrelated and are human made! Nature never creates an ecological issue, but humans out of their ignorance and irresponsibility creates issues of imbalances and disorders. Therefore, the pressing five ecological issues for future would be perhaps,

1. Whether humans (irrespective of racial, political and economic disparities )can globally collaborate with a single mind and goal to control climate change issues (solution is quite known to everybody that is reduction in CO2 output and conservation of natural systems; but the issue is that humans do not unite to solve it)

2. Whether humans worldwide decide single minded to reduce consumption of all kinds of resources - this is the only solution to the issue of resource depletion - 'the world has enough resources to meet every one's need but not the greed of a single person or nation'

3. Whether nations agree to better equitable  distribution of available resources to others worldwide to avoid the resource crunch in the current world? This is a very difficult issue, but diplomatic discussion with a firm determination towards sustainability can provide progress in this regard

4. Whether nations take a unanimous decision to avoid armed conflicts world over and to invest the amount to peaceful ecosystem restoration activities - marine restoration, soil restoration and the like

5. Whether nations decide to collaborate globally in medical field towards better health to citizens world over, instead of thinking of business at the expense of the unfortunate diseased and ill-healthy people

Of course, these are not just ecological issues, these are spiritual or moral issues. that is why ecology is also considered as a moral science for humans to progress on the earth; otherwise, humans need to face extinction in the near future!

It will be interesting to compile everyone's answer in some format--is that what you will ultimately do with our answers?

I think the world's biggest ecological questions that exist in 2016, we are not even aware of right now, but to add my top five, here they are:

1.) PSEUDOMONAS HOST TREE ELIMINATION?  The impact of cutting down the Pseudomonas host tropical trees from the seven site  that produce the rainfall on the planet--How much can we cut and still have rainfall in China, India and California?  We may have passed the tipping point in the last decade with the oil palm plantations in SE Asia.  See my questions on Research Gate at https://www.researchgate.net/search.Search.html?type=question&query=pseudomonas+rain

2.) DUST CLOUD'S IMPACT  ON EARTH"S RAINFALL? There are ancient Dust Clouds that form each year for the last 5,500 years that impact on the world's rainfall--like the Arabia-Pakistan and the family of North African Dust Clouds. see http://www.ecoseeds.com/cool.html and my questions at https://www.researchgate.net/search.Search.html?type=question&query=dust+cloud

3.) ECOLOGICAL RESTORATION OF ONE BILLION ARID ACRES TO STORE OUR CARVON?  The perennial arid lands native grasses are the best method to store carbon in the soil, and we have one billion acres worldwide that is considered unproductive, that could be set aside as Ecological Restoration Preserves to store our excess carbon that we produce each year, and at the same time by covering the soil with vegetation, stop the sun's heat from warming the atmosphere in those desert areas.  

4.) HOW MYCH OF THE NATURAL WORLD DO WE NEED TO PRESERVE AND HUMANS STIIL SURVIVE AS A SPECIES?  I asked that question at https://www.researchgate.net/post/Do_we_need_to_set_aside_35_of_the_planet_as_Ecological_Restoration_Preserves?  My guess is we need to remain in a pristine condition 35% of the planet, where we do no harvesting of the biota, no timber cutting, grazing, fishing, plowing, like the Sacred Groves in the Western Ghats of India.  And then do annual repairs to those ecosystems, to get them back to a pristine condition. 

5.) CAN ALL GUMANS ON THE PLANET DEVELOP ENVIRoNMENTAL AWARENESS IN TIME TO SAVE THEIR SPECIES.  Species have come and gone for eons, but we are unique position in that we have the flaw of separating ourselves from nature, and then do whatever we want with her, for our own selfish needs.  

Can all the humans on the planet develop some kind of environmental awareness and ethics, that each slice of bread we eat means that a native perennial grassland and all of the insects and animals that lived in that grassland died somewhere to produce that slice of bread?  Ar least to have the awareness of our actions on the planet and start to limit the impact, and be aware that we need to invest annually in reversing the damages already done in many parts of the planet?

Are we going to ask the right questions?

Right or wrong let questions come out! It's easy to ask questions, but difficult to answer them!